So about 4 days ago I noticed that my c drive had lost a few gigs, no big deal, but two days later suddenly my drive was in the red. I'm down to about 33gigs right now and it keeps dropping. I've run scans with Avira, Malwarebytes and Spybot but nothing has helped. Is it a virus or is it just some sort of system error? I haven't gone to any sites other than the ones I've always gone to for years now, nor have I clicked on any suspicious emails.