I noticed that in Windows 7 Ultimate 64-bit image there exist bootmgr.efi and winload.efi and I applied it to my computer. Then I edited my BCD to add an option to boot it. When attempting to boit in UEFI mode, Windows 7 always gets stuck at disk.sys and shuts down automatically. However there's nothing wrong when booting in legacy mode (boot winload.exe instead of efi). How exactly can I boot that Windows 7 in UEFI?
My computer originally had Windows 8.1 installed on it out-of-the-box and I turned boot mode to "UEFI with CSM" in BIOS settings.
Edit: Problem solved. My solution is to first boot into Win7 under LEGACY mode, install chipset driver (pre-downloaded from Intel) and then switch back to UEFI-CSM. Now Windows 7 no longer crashes at disk.sys.
But can anyone explain why it's related to chipset driver???
