Windows not appearing in boot manager

Hi! I’m a complete newbie to NixOS. I’ve had slight experience with other distros such as Manjaro and Arch, but NixOS has completely f’ed up my PC somehow.

I have 2 hard drives. One is a 1TB SSD which has Windows installed on it. The second one is a 1TB HDD which has NixOS on it.

When I installed NixOS on the second HDD, all occurrences of Windows and the SSD disappeared in my boot manager (motherboard boot selector and NixOS EFI boot manager).

Is there a reason for this? If it helps, I can’t mount the SSD because it’s saying that “the NTFS partition is in an
unsafe state”, yet I remember shutting it down completely when I went to install NixOS.

Any ideas?
Thanks!

Hi,

NixOS should not interfere with the motherboard boot selector. Mayve you messed up the bootmgfw.efi from windows. What do you have in /boot/EFI.

Did you try mouning the NTFS from an live usb stick. Maybe that works.

You properly have to do something like this systemd-boot - ArchWiki to make it work for the NixOS EFI boot manager. You can use this options to configure that

boot.loader.systemd-boot.extraEntries
boot.loader.systemd-boot.extraFiles