the download site is says "download maxblast 4" this program checks the hd in your computer and do partitions
I would agree with the above post of checking each main fodler on C: to find the size of each. Remember to "show hidden files". Go through each folder checking the size of each subfolder as well. Had the exact same situtation on a client machine. Kazaa decided to d/l about 30 gig of absolute crap. You know....those files that have names which Windows cant delete? Also, run a scandisk. If the fat is damaged, it can report incorrect free/used size. Scandisk would be my first check. Good luck