I run Win10 on an old hard drive. The drive itself seems fine (disks are spinning and my computer seems to recognize they are there), but it won't find my install of Windows. I just get a screen that says "Reboot and select proper media device." I try to enter the BIOS, but my computer won't recognize that I have a keyboard in. Anyone know what to do?

P.S. I had the same problem about a week ago, and unplugging and replugging all my drives worked then, but not this time.

Edit: Later the day this was posted, I swapped out my RAM stick for another and now my computer works. If this sounds like it'd be a temporary fix, please do respond. Post codes I kept getting were for an MSI board and they were 50, 51, 52, and 55.