Is it possible to repair UEFI that won't boot Windows 10 using Ubuntu 21 on a dual boot hard drive?
Solution 1:
Usually, if there is a friend whose windows uefi is damaged in dual boot, I make a bootable fdd uefi mode using rufus with the help of vbox on linux with usb extended pack. After finishing packing I use cmd on bootable usb installation windows cmd with shift + F10
sfc /scannow
bootrec /FixBoot
bootrec /ScanOs
bootrec /RebuildBcd
etc or recovery maintenance.