I used the reinstallation CD's Recovery Console and I let it run over night (CHKDSK /r). Unfortunately, after starting it up normally, I tried to run CHKDSK again from Command Console in Windows and am getting the same error message, 'Cannot open for direct access.' If I try to run it directly from the Run dialog, Command Console flashes onto the screen and is gone as quick as it came. CHKDSK from the CD said that it did in fact fix errors in the volume, but if that's the case, then why can't I run it from Windows still?
Update: I am now able to run Disk Defragmenter from Windows (whereas before it presented an error dialog). I can analyze but upon defragmentation I get sent to BSOD:
STOP 0x0000003F ( 0x00000000, 0x00000011, 0x0000022E, 0x0000003DF)