https://answers.microsoft.com/en-us/windows/forum/windows_10-update/windows-10-bootrec-fixboot-access-is-denied/747c4180-7ff3-4bc2-b6cc-81e572d546df?auth=1
Boot into Command Prompt from recovery media. Diskpart List disk *** Make sure the disk has a * in the GPT column. If it doesn't, then this is not a UEFI drive, so you should follow the instruction for MBR instead. Select Disk X list vol (Look for the 100-300MB partition with FAT32 filesystem, probably the last one) sel vol X assign letter=v: exit dir v:\ /a : Verify this is the right disk, no important files are on it format V: /FS:FAT32 bcdboot C:\windows /s V: /f UEFI |