I doubt you've filled it - an 80GB drive can hold roughly 80 million pages of
text, 80,000 million-byte bitmaps, and a hundred or so videos.
You may have a virus, or you may have worse trouble. So first of all, run
your AV software -- there's a slim chance that will fix things. It probably
won't, so you should look for a utility such as DFSee that allows you to
inspect and rewrite such things as boot sectors and sector maps. But if you
have _any_ qualms about using such a powerful utility, bite the bullet, and
take you hard drive to a shop that specialises in recovering data from messed
up hard drives. Be prepared to pay - if your data is important enough, you'll
be glad you did.
Do NOT reformat the drive - that will make it pretty well impossible to
recover the data -- not entirely impossible, but you'd need the kind of
expertise that CIA/RSA/FBI/etc use to recover data from wiped HDs, and I
don't think you can afford that. :-)
Wolf Kirchmeir, Blind River ON Canada
"Nature does not deal in rewards or punishments, but only in consequences."