I have installed Ubuntu alongside with Windows 10, and they are on different disks. Since the disk containing Windows does not have a UEFI partition and uses
C:/EFI/Microsoft/Boot/bootmgfw.efi to load Windows instead,
grub does not recognize the Windows bootloader.
If I boot from Ubuntu install USB and enter the grub command line, by running the following commands I can start Windows successfully:
chainloader (hd1,msdos1)/EFI/Microsoft/Boot/bootmgfw.efi boot
However, if I enter the grub command line of the installed Ubuntu on disk, when I run:
Error: invalid signature. If I add
--force option to
chainloader and then
boot, the screen goes blank and windows does not start up.
Can anyone give some suggestions on how to boot Windows from Ubuntu grub?