Looks to me like a problem with HD. Either it is dying or there is a bad cable connection. I suggest that you check on your drive's cable and plug out - plug in the cable.

If the errors reappeared after that, do this:
Boot with setup CD and choose repair console (I think that's how it is called with 2k... XP calls it recovery console) type in admin password and type

chkdsk c /r

It will scan for errors + look for bad sectors, which you probably developed. This might take hours to complete, depending on the HD size and amount of bad sectors.

If you are still getting freak errors, then your attention should shift from HD to RAM.

Reseating is a first step there.
Second step is (if possible) running with 1 stick at a time, to figure out the faulty one.
Third step is replacing it...

Hope it helps.

hi jg0426, it could be a faulty HD, or you can try to use some software to wipe out entirely your HD, or you plug your HD to another PC and check your HD through that PC