30. Windows Bootloader Missing / Multiple OS
Fix the UEFI bootloader if it is missing or has extra entries.
Restart in Diagnostics Mode:
shift + restart › troubleshooting › command prompt
Note
shift can be held during normal boot to get to the same menu.
First remove any extra EFI boot configuration data from other operating systems.
Remove extra EFI entries before rebuilding Boot Configuration Data
for Windows.
diskpart
list disk
sel disk 0
sel vol 2
assign letter=Z:
exit
cd Z:
cd EFI
dir
rmdir -S ubuntu
Note
Look for ~100MB FAT32 partition, this is the standard partition Windows uses
for storing EFI data. Adjust highlighted lines as needed for specific case.
ubuntu removed here. Boot and Microsoft should be left intact.
Fix MBR, scan for all OS’s on drive and rebuild Boot Configuration
Data for Windows.
bootrec /fixmbr
bootrec /scanos
bootrec /rebuildbcd
Restart machine.
If there are extra menu options, you may also edit UEFI boot options in firmware or use EasyUEFI to do it in windows directly.