Solved Lost Windows 11 dual boot when reinstalling Windows on C

Hey there,

I've looked into quite some troubleshooting guides to fix this but 99% is related to dualboot Windows 11 + Linux.
Here it is different. I have Dual boot Windows 11 with another Windows 11 installation.

Due to issues with AMD drivers I decided to reinstall Windows 11 by formatting C drive.
However, after doing this, I lost dual boot options for the other Windows 11 installation.

This is how my disk manager looks like:


Disk 0 (D) is the Windows 11 I cannot access anymore. It is also not visible in msconfig >> boot:


How can I re-add the other Windows 11 installation on D:?

Thank you for the help!

if there is a Win installation on (D:)

POLYSIUS said:

Code:

bcdboot D:\Windows /addlast

if there is a Win installation on (D:)

Click to expand...

Thanks! Will try that now. I tried this before but I didn't add the Windows after the drive letter.
Will report back if it worked!

Edit: This fixed it! Thanks a bunch!

But you should reduce the Partition size of (D:) and create a separate Data-Partition. It's much safer!

POLYSIUS said:

But you should reduce the Partition size of (D:) and create a separate Data-Partition. It's much safer!

Click to expand...

Good idea, I'll look into this next week. I use D: for work so makes sense.

You also can use/share the WinRE.wim from Recovery partition (disk 1) for the (D.) (disk 0) installation.
For the right command the bcdedit - result is to be posted first.
or boot into (D:) and type:
bcdedit /set {current} recoverysequence {recovery guid from disk1 OS}