Well I was able to reinstall Windows, but only with a clean install (no Windows.old or System Refresh were available). Apparently, one of the partitions was missing or corrupted that had Windows installed previously. Funny thing is, the HDD looks fine now, scans are not picking up any bad sectors. However, the machine won't boot in UEFI anymore and I've noticed that the drive is not GPT. I'm not sure if it's worth it to convert it to GPT and start over, but it seems like it's an OK HDD. Weird. Thanks again for the input received.