yeah - if chkdsk is failing that badly it might be a bad thing.
use another computer to make a bootable CD with some diagnostics. also i'd download and run Memtest to make sure you're not having memory issues. however, even without knowing anything of your situation i'd guess your HD is failing/has already failed.
we'll need some more specifics to help you much more. computer specs (including OS) and whatever problems you were having previously.