Yesterday I installed Bazzite for the very first time, on a venerable old gaming PC, and it looks like I have locked myself out of the pre-existing Windows 10 on that machine. Bazzite occupies all of /dev/sda (a fresh full-disk install), Windows slumbers on /dev/sdb. Both sda and sdb each have an EFI partition (vfat). I can boot into Bazzite just fine, but not into Windows any longer. Even if I select the sdb disk in my BIOS boot options, booting occurs from sda instead.
I have enabled os-prober via /etc/default/grub and run ujust regenerate-grub, alas to no effect. Running os-prober manually returns an empty result, which matches what I see in /boot/grub2/grub.cfg – no Windows menuentry to be seen there either.
It certainly does not help that the BIOS is more than 13 years old, and support has long since ended. If you have any ideas how I can set up dual-boot for Bazzite and Windows, I’d appreciate your input. Thank you.
P.S.: Yes, I did search both this forum and the Internet. 