Actually now that you have cleaned off that hard drive, if you have a spare HD sitting around, put it in the rig, back up the important stuff and then do a format, keeps some of the stuff safe.
Check out Gomez Peer
on how to make your PC work for you. Referred by dark2099 please!
Mini Rig: Biostar TP67XE / i5 2500k / Corsair H55 / 2x4GB PNY / XFX 7770 / Corsair CX500M / Win 8 64 bit / Thermaltake V9 Blackwidow