Since X220 BIOS upgrade cannot running on Windows 10, we need to use bootable CD to run the upgrade.
Beside, if you using UEFI boot for the Windows 10, you need to change the boot mode to both or legacy to run the CD to upgrade BIOS. After the upgrade complete, back to UEFI boot.
Since the official method did not work on 17093 (Might be hit bugs since it is insider build)
Remark: Make a full backup of your hard disk first
1. Use PartitionGuru software (Free edition) to convert the whole hard disk from MBR to GPT (Convert To GUID Partition Table)
https://windowsreport.com/convert-mbr-gpt-disk/
2. Converting Windows BIOS installation to UEFI start from step 3 to end step (The gptgen seems to be not work on 17093, that why I use PartitionGuru)
https://kheresy.wordpress.com/2016/05/17/convert-windows-to-uefi/
diskpart
list partition
select partition 1 (This is the MBR partition ~350MB to 500MB)
delete partition
create partition EFI size=100 offset=1
format quick fs=fat32 label="System"
assign letter=S
create partition msr size=128 offset=103424
list volume
select volume 3 (Which is OS installed volume)
assign letter=C
bcdboot c:\windows /s s: /f UEFI
Reboot the machine and change bios to UEFI and enable secure boot
For details:
https://kheresy.wordpress.com/2016/05/17/convert-windows-to-uefi/
