So I got a new computer. It came with a 2TB Toshiba HDD, I removed that (which was what the OS was originally meant to boot from) and replaced it with the C: and D: drives from another computer, which work flawlessly and boot the OS from the C: SSD
I then placed the 2TB Toshiba HDD that was originally the boot drive for this computer (and its only drive) back into the computer along with the other 2 and while Crystal Disk is seeing the drive, nothing else is. Not File Explorer, not Disk Management, nothing. I figured maybe it was just a hidden files/drives issues so I went to folder options and unchecked the option to hide hidden files, folders, and drives, rebooted, and looked in Disk Management again; still nothing. At the moment it has no letter assigned to it, its just showing on Crystal Disk as "Disk --"
Anyone have any clue how to remedy this? It is definitely installed correctly.