Yeah, it's just storage space.
I pulled out the 8GB ATA, and did an install on the C drive. Again, my system did not work. I guess that botched up the boot files' destination paths. Right now I'm in the process of buying a second SATA disk and putting Vista on it, migrating all my stuff into that from my current SATA disk. I'll unpartition the disk and put it to use as a dual boot with XP.
Thanks everyone for helping me figure this out!