A long while ago I had a dual boot working for Linux and Windows 7. I have since moved Linux
to a separate disk so when I want it I change the my OS I go into BIOS and boot off of another disk.
Anyway I forgot that the grub boot was still launching WIndows 7. When I naively upgraded to 10
today, the grub failed, and I can't get into Windows.
How do I restore/install a WIndows boot loader?