I have a dual boot install. I first installed Windows 7 in its own disk (C:) with the secondary drive disconnected. I did this because I know Windows has a tendency to mess with other drives. Then I connected a secondary drive and created a data partition (D:) and installed Linux in a third partition.
To sum up:
- Disk 1: Windows partition (C:)
- Disk 2: Data (D:), Linux (invisible from windows due to filesystem)
When Linux installed itself, it also installed GRUB in the second disk. So the Windows bootloader, which was installed in C:, wasn’t used. Still if in an emergency I disconnected the second disk or it failed, Windows 7 bootloader worked.
This has been working fine for years.
Now as part of a Windows Update this month, and I presume it is related to that update that nags you with the end of support message and a possible upgrade to Windows 10, Windows 7 has moved its own bootloader from C: to the data partition in the secondary disk (D:). There is now a bootmngr.exe and a Boot folder in D:, and there is none in C:.
Dual boot via GRUB is still working fine though, but I would like Windows’ own bootloader to stay in C: where it belongs. Will it suffice with copying bootmngr.exe and the Boot folder back to C:, or should I use Windows installation DVD to “repair” the Windows install? And If I fixed that disk alone, would the GRUB in the secondary disk still work?