How to Setup Windows 8 with UEFI BIOS in UEFI Mode

People who bought new computers in the last six months probably have UEFI compatible BIOS, however it is probably not enabled. Unfortunately the Windows setup procedure is obscure, defaulting to non-UEFI mode, or you have to manually activate it in your BIOS settings first.

The simple way to tell if you have UEFI boot mode or not is to watch Windows starting up. If you see the Windows logo when it boots, you are in old fashioned BIOS boot mode. However if you see your manufacturer or custom BIOS logo remaining whilst Windows starts you are in UEFI mode!

4 UEFI boots with BIOS logo instead of WIndows 2 4 UEFI boots with BIOS logo instead of WIndows 1

Why do this? Mainly because it enables exclusive UEFI and Windows boot features, such as:

  • Booting from drives larger than 2TB (for example 3TB drives are now cheap).
  • Super-fast start mode, booting in a few seconds including hardware (BIOS) initialization.
  • Additional protection for BitLocker (should you have a Professional edition Windows license),  e.g. safe PIN-only start-up (new feature in Windows 8).

Other benefits are less well documented, but basically it’s going to give you the best hardware integration possible (depending on your manufacturer, BIOS upgrade and device driver versions).

So it’s something which is only “nice to have” if you’ve already finished installed your PC, however a must for people with large drives or corporations wishing to maximize the security of their computers. Most importantly it’s something you have to get right at the start, because you have to reinstall your PC completely (no upgrade possible) to switch from BIOS to UEFI. Shame Microsoft didn’t think of that, but then they didn’t allow 32bit to 64bit upgrades either, which is disappointing because they should promote support for the new hardware technologies.


  1. Make sure your Windows setup USB stick is formatted as FAT32. The UEFI boot of Windows setup does not support NTFS! Again strange, because it is able to boot in UEFI mode from NTFS on the hard drive after installation!
    1 UEFI USB Disk must be FAT32
    Then copy all the files from the Windows setup ISO or DVD onto the USB stick, including most importantly the “EFI” subdirectory and boot files. You can double-click an ISO in an existing Windows 8 machine to mount it as a drive letter, for easy access to copy. You cannot use the Windows 7 USB Boot Tool from Microsoft.
  2. Ensure your BIOS has been configured for UEFI boot. Here’s an example of the necessary settings on my ASUS P9X79 motherboard:
    2 UEFI BIOS settings 12 UEFI BIOS settings 22 UEFI BIOS settings 32 UEFI BIOS settings 42 UEFI BIOS settings 5 2 UEFI BIOS settings 6
  3. Boot Windows setup in UEFI mode, causing Windows to automatically install with UEFI boot drivers. To do this you have to select your USB device in UEFI mode. The ASUS BIOS shows two entries when a device supports UEFI, one with and one without. So make sure you choose the one with UEFI in the name when two entries are displayed! You usually select the start-up device from the BIOS setup menu or a mini-start-up menu (e.g. F8 on ASUS machines):
    3 Force UEFI boot of Windows setup USB from F8 menu3 Force UEFI boot of Windows setup USB from BIOS config
  4. Optional: Convert your disk to GPT (GUID Partition Table). Do this if your disk is empty, you want to boot from a disk more than 2TB or you don’t mind losing any data on the disk.
    Select advanced options from the Windows 8 setup main menu.
    Open a command prompt, enter “diskpart”.
    Enter “list disk” then identify the disk to install on (the size is a good guide) and its number.
    Enter “select disk #” where # is the disk number.
    When you successfully selected the correct disk (be 100% sure) enter “clean” which deletes EVERYTHING on that disk (!).
    Finally, the most important part, enter “convert gpt” to prepare the disk with a GUID Partition Table, which the UEFI boot mode can use to access the full (greater than 2TB) storage.
    Exit and reboot, selecting UEFI mode again, following on through the normal installation to setup Windows in UEFI mode 🙂
    Note we do not bother creating a primary partition or formatting because Windows will do that, we just need the bare disk with the right partition table.


This could have been easier. I think the main problem is there is no visible information to tell the user they have UEFI capability, or any option to explicitly install Windows in UEFI mode. I wonder also if it would be technically possible to write the correct data to the disk for a UEFI installation even from a non-UEFI boot stick. For example Microsoft could detect your hardware then show a warning message that you are not installing Windows in the optimal configuration. They could have done that with 32bit installations on 64bit hardware too.

So you probably don’t have UEFI installed, but following a straightforward procedure as demonstrated here could bring some benefits for you. With the price of hard disks falling and the annoying 2TB limit in a traditional (non-UEFI) Windows installation, I think more people will be searching for a UEFI solution now. Further, since Windows 8 is generally available the manufacturers appear to be rolling out UEFI as a standard. Actually UEFI was supported in Windows 7 but nobody really knew about it or had hardware for it. Now is a good time to adopt this technology in it’s second generation (Windows stable) form.

Further Reference

Installing Windows on UEFI Systems

Firmware and Boot Environment

28 thoughts on “How to Setup Windows 8 with UEFI BIOS in UEFI Mode”

  1. Nice article – but I’m still confused: If I buy a WIN8 PC and enable UEFI then I don’t have to go through your procedure – correct? (still unsure of the benefits of doing so).

    1. Thanks. Unfortunately you do have to re-install Windows to switch into UEFI mode. Crazy I know. Like I commented, MS should really be agnostic to processor and BIOS during the install because all they are really doing is copying files to the disk and generating initial registry entries to enable the first boot (the rest of which is Plug and Play).

      At work I recently had to reinstall some “old” IBM System X servers from the year 2010, and was surprised to see UEFI already in the BIOS. Yes even in those “old” days when it was totally state of the art standard these boxes had support for it (explains why they are so expensive).

      Anyway, as another diverse example that went the same way… just go into the BIOS, switch off all the legacy stuff, enable the UEFI stuff, boot in UEFI mode. Okay it was not AS easy as the ASUS workstation motherboard… I had to use the IBM BIOS “Boot Manager” to add an entry and browse the boot media for the right EFI boot file.

      It was also a good example that regardless of the system (I installed both Windows/Hyper-V Server 2012 and VMware ESXi in UEFI mode) they all have some kind of “\EFI\Boot” or “\Boot\EFI” subdirectory on their boot media. In the case of VMware there were two files, so I just tried each until it booted into setup 🙂

      Also after the first boot the VMware failed to update the Boot Manager with an EFI entry for the new system disk (Windows was better in that respect – fully automatic). But knowing the basic principle, that it’s just looking for an EFI boot file, it was easy to work-out how to add it myself. The EFI file is nothing more than a new version of the old fashioned (and very limited) “boot sector”. In the process of installing the UEFI system on the C: drive it also just copies an EFI boot file into a “Boot” or “EFI” subdirectory.

      Getting back to your question, in theory a fully UEFI compliant pre-installed system “should” be installed in UEFI mode. But it’s up to the “system builder” (manufacturer) to decide. Taking the 64bit example (remember when Windows Vista was released), there’s not much hope. Because in practice the new 64bit compatible systems were sold preinstalled with 32bit Windows as an “easy choice” to avoid support calls / additional manufacturer costs. So you’re probably looking at a re-install. Just make sure you get a copy of the install media as some pre-installs won’t install stand-alone, only as a “system image restore”.

      There’s one other important point I have to edit into this article soon. That is “GOP” (what?!). Yes I didn’t work that out either until I read more about UEFI and tried to switch off ALL the legacy options of my workstation, which has a NVidia GTX 560 graphics adapter. GOP is the equivalent of UEFI for graphics card firmware. Because detecting the video is one of the most limiting factors of the “fast boot” UEFI scenario, you won’t get a few seconds boot time unless you also have a GOP card, because it will have to run in compatibility/BIOS (SVGA) mode to query and initialize the graphics adapter(s).

      In practice, if you have a motherboard which is UEFI compliant and has built-in graphics, then you must have a GOP capable graphics chipset on-board. I can confirm this on my son’s Asus Sabertooth Z77 board, which was able to fully switch off even the “Compatibility Support Module” for full speed start-up (see various YouTube videos comparing start-up times of different boards with Windows 8/UEFI mode).

      However, if you install add-on graphics cards, there is bad news. For example, NVidia publically stated they cannot produce a UEFI firmware update for their 500 series cards because there is physically not enough space on the EPROM. I have two such cards 😦

      Same goes with other add-on cards, if they don’t support UEFI you have to leave some part of the “legacy” initialization switched on. Most people won’t have add-ons besides graphics so that’s no issue really. The big IBM server had UEFI for everything; the network cards, management and storage adapters. There was even a “WebBIOS” graphical environment to manage the RAID array at pre-boot! In the past it just had a limited text interface and required booting into a large “ServerRAID” DVD to do anything useful. That’s very impressive.

      Not to worry for the average user, you just need your mainboard and any optional graphics card to support it. Just be aware if you buy any future cards like network or storage adapters (which usually have pre-boot support/BIOS extensions) that there should be UEFI support on some models on the market, which are a preference if they are not too much more expensive.

      In short just get a copy of the media if you buy a pre-install so you can re-install as UEFI yourself. And double-check the spec of any add-on graphics card to make sure that has UEFI/GOP capability. Check out those YouTube videos about UEFI boot. It may help you find the best board. It’s pretty amazing when you see how fast they start. This one is good:

      Just be aware some of the old Windows 7 UEFI videos reported no significant advantage. Depends on your motherboard. Any new one with Windows 8 should achieve the desired few-seconds boot, especially if you couple that with an SSD too 🙂

  2. hey i have lenovo essentioal g480 core i5. in bios settings it shows only “UEFI enable or disable ” i. enabled it and follow ur procdure. Windows is installed but as u said that ur laptop manufacturers name appear instead of win8 logo on uefi boot, it doest happen in my case also booting has goten more slower ..
    i also checked my bios by “msinfo32” it showa my bios is UEFI… still its not like u said at all …
    kindly help.. reply soon…

    1. You need to ask on the Lenovo support forums. The quality and ease of activation depends on the motherboard and seems to be improving over time, but there are many settings involved and it’s up to the manufacturer to want to support UEFI and fast start-up, so I would check:

      1) Install the latest chipset and Intel Rapid Storage drivers.
      2) Make sure any SATA options in your BIOS are set to either AHCI or RAID mode (not legacy or anything like that) if you are using RAID0 or SSD caching.
      3) Also check your BIOS for something similar to the Compatibility Support Mode of ASUS, any options which have a Legacy or UEFI option. Go for as many non-legacy options as possible, but perhaps not all because you may still want to boot from non-UEFI USB stick images, for example for BIOS or firmware updates (other bootable images which not normally UEFI).
      4) Check the Windows power options in control panel to ensure fast start-up is enabled (should be on by default).
      5) Not sure if you have a laptop or desktop, but… If you have a gaming graphics card make sure the firmware is updated, many are not UEFI compatible (even GTX 600 series for example) or have a “hybrid” mode which can cause trouble. You need a GOP compatible card to get full speed.

      Regardless of start-up speed, other reasons you might want to leave it in UEFI mode are:

      1) Intel Smart Connect software – get Windows RT style “always on” behaviour, e.g. checking emails whilst “switched off” without draining the battery (claimed but I really don’t know, seems like you can’t beat ARM at “always on” and low power consumption).
      2) Ease of configuration within the BIOS itself, usually full graphical access to other option card BIOS screens, e.g. full RAID or network card configuration without loading any OS/utilities first.

      But as I said you need to check the forums. A good sign would be some kind of UEFI section in the owners manual or whitepaper on the manufacturer’s support web site. Good luck!

      1. thankyou for your resopnse.

        i cant access my bios . when i hit F2 or F8 nothing happens. I have checked all the function keys… ifinally endup with my desktop…

        i tried to update my bios (using update file downloaded from Lenovo site) but when i run it my system stops working.. i cant even able to move my mouse…..

        i have tried every thing like:

        1) turning fast start up off
        2) using win8 pc settings … general… advaced setngs… trobleshooting……and so on . I dont even get the option for “Change UEFI firm ware settings” there.
        3)removing my battery and hard drive and then turn on my laptop but still no success
        4) reinstalling windows

        now what should i do!!!!!!!

      2. Well first the idea was to switch anything like fast start-up on not off. As for the rest you need to either leave it as it is if it works, or contact Lenovo support to ask them why it doesn’t run well with UEFI. I can’t help with different hardware and speed is not the only benefit anyway. As I said it’s up to the manufacturer to think about if and how well they want to take advantage of UEFI. The older the machine the less likelihood of any benefit. Even if your machine is new manufacturers may decide not to bother with new technologies as long as possible. The desktop PC manufacturers (ASUS, Gigabyte, etc…) appear to be the most advanced.

  3. Hello,
    Can you help me? i whant to install 2 windows on dell 7010 (win 8.1 and win server 2012). I have installed win 8.1 on hdd(3TB using UEFI) but when i tray to install win serv. 2012 an error apear (The product key entered does not match any of the Windows images available for installation. Enter a different product key). Can you help me?
    Best regars,

    1. That message has nothing to do with UEFI and the same Microsoft key will work the same way in both UEFI and BIOS modes. As we are talking about Windows Server you also have to make sure you have the ISO image for the right edition. If you were asking about Windows 8 I’d also check you had the X64/64bit ISO. But Windows Server only works on X64 since 2008 R2 which is also what UEFI requires (doesn’t work on 32bit that’s legacy BIOS only). So the only possible causes are the installation image flavour or the validity of the key.

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  5. Hello,
    As i understand UEFI can read only FAT32 formatted USB flash sticks. In order to boot from USB under UEFI. But what if i want to install win8 from DVD, do i have to format my SSD to FAT32 in order to boot under UEFI ?

    1. The DVD should work if your BIOS allows you to boot in UEFI mode from the optical drive. It’s also a standard format (not NTFS which seems to be excluded by the UEFI boot standard for some reason). But I haven’t tried that because I normally install from downloaded ISO images.

      What you can’t do, which makes it more difficult, is install the UEFI OS mode from previously installed BIOS mode (legacy) installation of Windows. Same way you can’t install 64bit from a 32bit booted OS even if the hardware supports it. It’s technically possible but I think Microsoft want to test that your machine really boots in UEFI mode before overwriting your disk with a system which might not work. Shame because I’d prefer that option and it would make things a lot easier.

      Anyway, in case you can’t boot UEFI from DVD for some reason, then you can still format any extra hard drive in FAT32, expand the ISO or copy DVD contents there then boot. To be clear, we don’t require FAT32 for the Operating System, that will be NTFS or the new “ReFS” new server OS’s. Only the installation media must be in a UEFI supported format (FAT32 or DVD/UDF perhaps). In case you have trouble creating bootable drives (USB or hard disk) I’d recommend the “Rufus” boot utility available here:

  6. Hello,
    I have HP Pavilion g6 1360su. My BIOS is Insyde H2O version F.6A. In my BIOS settings i do not have an option to boot from UEFI. But i have an option called UEFI Diagnostics and it is used for a memory check, disk check etc. I have installed my Windows 8 64-bit from the DVD disc and it installed in Legacy BIOS. Is there a chance for my laptop to support BIOS?

    1. Did a quick search and scan read; it looks like there is some kind of toolkit you can download to switch to UEFI BIOS boot mode. But it doesn’t sound easy.

      Ok in the simplest form, what UEFI boot is really just booting a “*.EFI” file. If you don’t get a direct boot option with these tools, then look for an option to add a boot entry/browse for an EFI file to start from. Because that’s all you really need, to tell the computer to boot the EFI file.

      After all the EFI file is nothing more than a new style of master boot record. The old BIOS used to be hard coded (and limited to) starting from the tiny first blocks of the hard drive. UEFI is flexible and unlimited (in this sense at least). It can boot from any EFI file it is capable of accessing at start-up, hence the requirement for FAT/FAT32 and other basic formats like UDF/DVD, and why it can’t do NTFS because they chose not to include that in the standard (shame).

      Sorry I can’t help with general hardware questions. Good luck anyway, maybe you get it working if you read that toolkit carefully and seek help on other sources.

      Right, for anyone else now… DON’T post hardware specific questions here. I’m not a support desk! With respect, any future comments like that will just be trashed.

  7. Thanks for this article, it was very interesting. However, I have had success simply enabling UEFI boot in the legacy BIOS options, because I—well, let’s just say bought—Windows 8.1. Here’s how I did the deed. (I’m using Pro, so this might be why).
    1. (I assumed, at least) that when you do install Windoze, Windoze places an EFI folder on the root of your active drive.
    2. I turned on Secure Boot/UEFI in BIOS.
    3. I rebooted, and UEFI was enabled.

    1. Windows requires secure boot keys to be added, so I don’t see how you could install non-UEFI then just enable it.

      You are probably still booting Windows in BIOS mode in a UEFI “capable” (but still BIOS compatible) mode. Try turning off legacy BIOS (full UEFI/CSM disabled – names depends on manufacturer). Then if you also have a GOP compatible graphics card and it boots it could confirm you have UEFI mode (if you got the right setting and your board really does turn off all legacy in this mode).

      Still looking for a way to confirm from within Windows what the current BIOS mode is, Device Manager still says ACPI PC (the old method of discovering ACPI or non-ACPI HAL does not work for UEFI). Guess I’ll have to write a program or its hidden in WMI management information somewhere (could be scripted).

      As this would be a significant feature if it works I will get around to testing along with a utility to verify the result. So far the best way to see if you are booting UEFI is that most manufacturers put their own company logo over the boot time animation. If you still see the blue Windows flag during boot you’re probably still in old BIOS mode.

      1. Hey Code Chief, really a nice article!
        I bought a new PC some days ago that was empty (no OS), and before installing Windows I entered the BIOS and found… Mr. EFI at its place 😀 Then I started to search how to setup Windows on a UEFI machine and… here I am 🙂

        I just wanted to say: even if the UEFI specs do support startup from a MBR partitioned disk, Windows does not, so we have these implications:
        if Windows has been installed in UEFI mode, then it must have been installed on a GPT disk;
        if Windows has been installed in BIOS mode, then it must have been installed on a MBR disk.
        So the obvious fact would be: if you open the Disk Management tool or Diskpart or other partitioning tool and look for the partitioning scheme of the boot disk, you can state how Windows has been installed on that machine 😀
        Is this correct?


      2. Hey you’re right, Nice one!
        I confirmed this by searching for the official docs on MSDN…

        Which states..

        Note Windows only supports booting from a GPT disk on systems that contain Unified Extensible Firmware Interface (UEFI) boot firmware.

        That’s a good workaround, thanks for posting it 🙂 UEFI seems to becoming more and more popular (in demand rather than just nice to have) so I think an update to this article with all these tips visible up-top is due soon.

  8. Hi Code Chief! I find your post very interesting and you are very well verse with the topic. I hope you can help me out with my problem.

    I bought a Sony Vaio from Europe 5 months ago and works perfectly good. However, I encountered recently a Hard Disk Click Sound which technicians advised me to replaced with a new one. I just did. The original drive was 750GB and I replaced it with 1TB hard drive. My mistake was, I was not able to create a recovery disk from before. So I tried to install Windows 8.0 under UEFI(following all the procedures you posted). The setup runs until the final stage but it shows an error message saying “Windows could not update the computer’s boot configuration. Installation cannot proceed”.

    It really puzzled me, because when I tried to install Windows 8 under legacy mode, it completes the setup without any problems. But under UEFI, it never was. I tried to read more than 100 articles just to know how could it be possible but your posts seems to be the logical one.

    I hope you can help me with this error message. I really wanted to run Windows 8 under UEFI mode. My Laptop model is Sony VAIO SVE1512Y1ESI

    Thank you Code Chief! I Looking forward for your response and help. More Power!

    1. Hi Raymund,

      The final stage of setup (which fails on your laptop) is to write/configure the “secure boot entry” into the UEFI BIOS, which could actually be stored with a TPM (Trusted Platform Module) chip if your laptop has one. That is likely because the point of TPM is to prevent removal into a new system, so they bind to hardware. Since the hard drive changed, if the hard drive was TPM aware it becomes locked to a system. So you need to clear-out the TPM data too.

      Even without a TPM, you should have a section in your UEFI BIOS configuration screens which allows you to manage the secure boot keys. In both cases then, choose the options to clear/remove all entries. If you have a TPM you should a further or merged set of options to disable/enable/initialize/clear the TPM chip/keys. Both must be in an enabled state for Windows to write the entries. Another option which could be blocking it is any “Antivirus” option you may have. Originally designed to prevent writing to the boot sector via legacy BIOS but may also be interpreted as a desire to lock writes to the UEFI secure keys in UEFI mode.

      If you cannot get the boot entry written automatically at the end of Windows setup, the last option is to try and add the entry yourself… I was able to do this on an old IBM Server with a similar problem, it allowed manual entries and provided a file selection screen as UEFI boots from files not a boot sector. Basically you need to select the “\efi\boot\bootx64.efi” file on the system disk.

      Same goes with any other system, for example I also got VMware ESX server running in UEFI on the same machine by browsing to a different path; just try them all till it works if you don’t know 🙂 Same with bootable USB sticks too. At least if this does not fail, you have something new to search the forums on, i.e. your laptop model and TPM/secure boot entry write issues.

      One point of caution: never clear TPM or secure boot keys on a working system/partition! You may not be able to gain access to it again and if it’s secured with something like BitLocker the data is gone forever! So these measures are just for initial setup.

      Good Luck!

  9. Hello Code Chief,

    To quote

    “f you cannot get the boot entry written automatically at the end of Windows setup, the last option is to try and add the entry yourself… I was able to do this on an old IBM Server with a similar problem, it allowed manual entries and provided a file selection screen as UEFI boots from files not a boot sector. Basically you need to select the “\efi\boot\bootx64.efi” file on the system disk.”

    Can you tell me how to do this part? I was thinking the same way as you do that perhaps a manual enry will do the miracle. However, I am not sure how to do that.

    Awaiting for your answers. CHeers.

  10. It’s totally specific to your make and model. If you can’t find any of those options I mentioned in the BIOS, then your machine may simply be incompatible. Then your only options are to try updating the BIOS if available or contact your manufacturer’s support forum. Internally there is obviously some API for Windows or any other UEFI OS to write the secure boot entries. But I don’t know of any tools which generically poke the UEFI BIOS. It’s really the job of your BIOS setup screen to do that. Look for advanced mode too, that’s about all I can suggest. Good luck!

  11. Hey, I’m here again 😀
    I finally had the time to make some other tries, and found something interesting.

    First, you can watch if Windows has been installed in BIOS or UEFI mode also by looking at msinfo32. Now I don’t have the EFI PC at my hands so I can’t give you the right parameter to look at, but it’s really simple: open msinfo32, and on the right part just search for something like “BIOS Mode” or similar.
    Indeed, from there you can also watch if Secure Boot is disabled, enabled or unsupported.

    Second, if you’re in doubt DURING WINDOWS SETUP, that is you don’t know if setup has been started in BIOS or UEFI mode, press Shift+F10 to open a command prompt and type these two commands:

    wpeutil UpdateBootInfo
    reg query HKLM\System\CurrentControlSet\Control /v PEFirmwareType

    If the answer to the last command is 0x1 then you’re running in BIOS mode, while if it’s 0x2 enjoy 🙂 ‘coz you’re running in UEFI mode.

    Third, I discovered that the showing of the manufacturer logo instead of the Windows logo may or may not tell you if Windows is starting in EFI or BIOS mode. That is: if you see the manufacturer logo while loading Windows you can assume that you’re in EFI mode, but if you see the Windows logo you can’t assume you are in BIOS mode. It’s just a BIOS setting, in my case (American Megatrends BIOS) it’s called:

    Boot Logo Display

    and can assume three values: Disabled, Full Screen and Auto.
    Disabled = do not show any OEM logo (and show POST results instead) during boot, and show Windows logo during Windows loading.
    Full Screen = show the OEM logo instead of the POST results during boot, and show Windows logo during Windows loading.
    Auto = show the OEM logo instead of the POST results during boot, and show the OEM logo during Windows loading.
    To avoid displaying the OEM logo during the POST phase, simply choose Full Screen or Auto, and set POST Delay Time to 0sec.

    Fourth, I thought this is a useful information too: Windows Vista/7 x86 cannot be installed in UEFI mode. Windows 8/8.1 x86 can be installed in UEFI mode only if the EFI machine is a 32-bit machine. Windows Vista, 7, 8, 8.1 x64 can always be installed in both BIOS or UEFI mode.

    Fifth, maybe this could help somebody. When I first installed Windows without CSM, all went ok but I was seeing a black bar on the right of the screen and the left part of the screen was cut away. I discovered that was a monitor problem, and I had to re-calibrate it to get the right picture. Maybe the GOP protocol and the VGA port needed an adjustment to work properly.

    That’s all I discovered for now, thx for reading 🙂
    Bye bye.

    1. Hi Nico,

      Thanks for those tips. Just a few comments…

      1) EFI existed a long time before UEFI so I think it’s best to use the full UEFI acronym else people may get confused. They are the same Intel Architecture initiative at the core, renamed in 2005 (probably after the failure of the IA64 compared to AMD64 architecture, but just my guess) and there are a lot of files and documents all over the pace about the original/legacy EFI. I think it’s safe to say only “UEFI” or “Unified EFI” refer to the capabilities we’re talking about here.

      2) Quite sure I read UEFI was 64bit by design and anything 32bit on UEFI is only working via compatibility features so is really BIOS emulation on top of UEFI. People should not be mislead into thinking their 32bit installed on UEFI hardware has the same benefits. Just no negative sides if their manufacturer got it right. Needs clarification.

      3) Your Windows Setup (WinPE) registry key got me searching on an already installed machine and I found you can also find a key there for UEFI. If this key exists you have UEFI “HKLM\SYSTEM\CurrentControlSet\Enum\ACPI_HAL\UEFI\*” where * is a number, mine was zero. Interesting but of course MSINFO32.EXE’s “BIOS Mode” you mentioned is much easier for end users. Real shame Microsoft did not print this on the main system information window and Device Manager PC type. Have to take a look at the Windows Driver SDK sometime for the proper API, a little tool would be useful.

      4) More on #2 I know the MS Surface I have is UEFI but only a 32bit system. Checking the registry key in #3 confirms it’s UEFI. I wonder then are Microsoft letting these small systems run with UEFI compatibility mode to save memory (on small 2GB devices where 64bit would just waste RAM). Probably the same for all those new Surface-like devices too, e.g. ASUS pads. They must still get secure boot in 32bit UEFI mode then as I heard the Surface has secure boot locked on and set to prevent unsigned executable files from running. There’s a nice “how to root the Surface” article which explains that.

      Now we have a lot more information which is good. I want to re-write this article with everything at the top already included. I bet too that your display issue is a GOP compatibility bug, because the way I see it that’s the point of GOP to skip the whole MS-DOS style legacy BIOS VGA detection rubbish. If you’re lucky you’ll get a (UEFI) “BIOS” update for your graphics card to fix that. Only other thing could be specific to your monitor but that would be rare.

      Even without GOP UEFI boot mode is still faster and easier to configure. The latest UEFI thing I think really justifies it is the SSD hardware encryption support. Last motherboard I got from ASRock even had a full (UEFI) “BIOS” update and driver download client built into the “BIOS” menu system, so we can see the manufacturers are really taking advantage of it now.

      p.s. I still feel like I should write “BIOS” in many situations. UEFI means some kind of universal blah blah… *firmware* interface then I suppose we should all write “Firmware Update” and “Firmware Configuration/Setup”. Sounds strange, so I think at least the word “BIOS” will stick around for a lot longer like the confusion 🙂

      1. Yep, for EFI UEFI you’re right, my mistake.
        I had a “full immersion” into this stuff and, to simplify my writes, I often used EFI as a shortcut to UEFI. Now that the immersion is ending I’ll strive to forget the “EFI” word.

        As for the 2nd point you write, I also thought that all 32-bit installations couldn’t run on a native UEFI system… but I read somewhere that Microsoft decided to support x86 native UEFI systems on their Windows 8/8.1 x86 OSes in order to let them run on x86 Intel Atom processors… not really sure where I read that, but I found this (maybe it’s sufficient):

        Windows support of UEFI
        The following Windows editions include support for UEFI:
        • Windows 8.1 and Windows® 8 support native UEFI 2.0 or later on 32-bit (x86), 64-bit (x64), and ARM-based PCs. They also support BIOS-based PCs, and UEFI-based PCs running in legacy BIOS-compatibility mode.
        • Windows® 7, Windows Vista® with Service Pack 1 (SP1), Windows Server® 2008 R2 and Windows Server® 2008
        ◦ Support UEFI 2.0 or later on 64-bit systems. They also support BIOS-based PCs, and UEFI-based PCs running in legacy BIOS-compatibility mode.
        • While in UEFI mode, the Windows version must match the PC architecture. A 64-bit UEFI PC can only boot 64-bit versions of Windows. A 32-bit PC can only boot 32-bit versions of Windows. In some cases, while in legacy BIOS mode, you may be able to run 32-bit Windows on a 64-bit PC, assuming the manufacturer supports 32-bit legacy BIOS mode on the PC.
        [End of quote]

        Thus it seems that Win8/8.1 x86 can be installed on UEFI x86 systems in both native UEFI mode and legacy BIOS mode. But of course, to do the first you had to own a 32-bit UEFI machine that I think it’s uncommon.
        Another thing it’s coming to my mind (but I’m just thinking aloud) is that if the legacy mode is enabled on a machine, Secure Boot can’t be enabled too, because it couldn’t check for sings over legacy OpROMs. So if Surface has Secure Boot permanently enabled it should follow that it’s running in native UEFI mode.
        Actually I have to try to enable both Secure Boot and CSM and see what happens…

        Cool you’re about to refresh this article, UEFI is no more the future, is now 🙂
        P.S.: you could also write that it’s not needed to use diskpart to convert the main disk to GPT during Windows Setup. You can simply destroy all the partitions using the GUI provided by setup, and create the destination partition. Windows automatically converts the disk to GPT and creates the MSR, the recovery partition and the ESP.

        Bye, Nico.

      2. Hi.
        Fresh news: found out that on Device Manager there exist this item (probably only if Windows is installed in UEFI mode):

        Firmware > System Firmware

        which, under Location, says:

        “on Microsoft UEFI-Compliant System”.

        Thus it remains just a pity that Microsoft didn’t put it on the main System Information control panel page.


  12. Hi Code Chief,
    You are an absolute star.
    I have spent about 12 hours trying to demystify the UEFI BIOS and associated HDD GUIDS and have had an absolute nightmare with a ASUS F551M laptop without a CD/DVD ROM after wiping WIndows 8.1 from it to re-install WIn7 for a friend who has just left hospital and is housebound for a while. So they desperately need their PC but hated Windows 8.1..

    I have tried innumerable tools including: BartPe, various USB bootable disk ID recovery tools, upgrading firmware, sysrescueCD, netboot, USB device CD emulators etc etc etc with zero joy whatsoever.

    Continually received Windows cannot install to hard disk 0, partition 1 etc.

    Just created a UEFI USB disk with Win 7 64bit ISO as per your instructions, selected UEFI USB in boot options menu and it went straight in, re-partitioned and formatted my disk and the Windows 7 install is chugging a way quite happily.

    Many, Many thanks, I now have my weekend back.
    Many thanks again.

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