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!
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.
- 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!
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.
- Ensure your BIOS has been configured for UEFI boot. Here’s an example of the necessary settings on my ASUS P9X79 motherboard:
- 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):
- 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.