Unified Extensible Firmware Interface

Convert Windows 7/8/10 Installation from Legacy to UEFI Without Data Loss (Simpler Method)

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• published: 16 Nov 2015
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How to convert Legacy to UEFI Without Data Loss (Simpler Method) I previously had a tutorial for this at https://www.youtube.com/watch?v=Qk6_K9hVu_k but is was fairly complicated. This is a simplified process. Please note that this method has been tested only for 64bit installations. 1. Download gpt-fdisk (gdisk) for Windows. 2. Copy the binary to a known location. 3. Boot into Windows Recovery Environment. - If you don't have one, download Windows10ISO from: https://www.microsoft.com/en-in/software-download/windows10ISO - Create a bootable USB by following https://www.youtube.com/watch?v=Q8gQuYekACU or by burning the ISO to a DVD. 4. Shutdown Windows and boot using this media (Legacy or UEFI Mode). 5. Get to the command prompt. Either by pressing Shift+F10 or by navigating to it. 6. Go to diskpart and find out the disk identifier for your Windows installation. diskpart list disk sel disk X list par 7. Navigate to the location where gdisk binary is kept and type: gdisk -l X: (Replace X with the disk number) This will list out the partitions available in the disk. Make sure this is the one your want to convert. 8. Now, convert the partition table from MBR to GPT. gdisk X: Type w to write changes. Press Y whenever prompted. 9. Type the following commands: diskpart sel disk X (Replace X with the disk number) list par # Now we make some space for our EFI partition # Note the partition number of the partition which you want to shrink sel par X (Replace X with the partition number) # You may delete the System Reserved partition and replace it with the EFI partition. To do that, type: # sel par X (Replace X with the System Reserved Partition) # del par override # The shrink command is not required if you do the above two commands. # I'll just go ahead and shrink. 500MB extra doesn't matter to me :D shrink desired = 200 minimum = 200 # The following commands are common: create par efi format fs = fat32 quick # Format this with fat32 file system assign letter = Z: exit 9. Copying boot files. Find out the partition in which Windows is installed. Note, the partition letter here might be different than the partition letter you see in Windows. Perform dir X: on each partition letter you think can have the Windows installation and confirm X. Then type: bcdboot X:\Windows /l en-us /s Z: /f ALL 10. Done. Now reboot in UEFI mode. Let's check if we have indeed booted in UEFI or not!! Type msinfo32 in run and hit enter. Yay!! Done! Windows 7 Users Please Note: For Win7 users, one can either use a Win8 or Win10 USB/DVD, or use the newer version of bcdboot.exe from https://drive.google.com/file/d/0B8d4Lb_KJbfdNHdtUWE4eUhZOG8/view?usp=sharing Music: 00:00 - 05:16 Daily Beetle by Kevin MacLeod is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1500025 Artist: http://incompetech.com/ Music: 05:17 - 11:53 Cryin In My Beer by Audionautix is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) Artist: http://audionautix.com/ Music: 11:54 - 14.25 'Calypso Beach Walk' By 'Doug Maxwell/Media Right Production' Wanna support me? Visit: https://www.patreon.com/nehaljwani