I had a Windows 10 installation working fine for a while now and I wanted to try dual booting so I used Debian since I heard its stable.
I’m fairly certain I turned on “dynamic disk” without knowing what it does and i’m assuming that was part of the problem.
After that, I booted into the Debian USB flash drive, installed alongside Windows (I made sure to give windows like 80 GB of free space so I didn’t delete any data) and Debian worked, but when I went into BIOS to boot back into Windows I was met with an “Automatic Repair” screen.
It couldn’t fix the issue, and it had a bunch of other options like using a system restore point but all those options just gave me errors (I’m 99% sure I had a restore point too) so eventually I looked at a bunch of forum posts and nothing could fix it.
I was able to copy all data on the drive but I really don’t want to have to reinstall Windows so if anyone can help I’d be very thankful.