It seems the something did happen to the NTLDR file, as it doesn't boot no matter the slot it's hooked up to. I booted another hard drive through the computer, and connected the problem hard drive through a USB adapter, but it comes up as "Backup" in My computer and contains a folder called Norton Restore. It is labeled as an 18.5 GB hard drive, when the whole thing should be around 50. I'm not sure what happened there, but I was hoping to be able to fix the problem by going into the hard drive, but that's not possible since the only visible partition is the "backup" one.