My computer has an auto-immune disorder?! Oh nose!

I don't even know how this happened. But right now my computer is frustrating me more than you. Yes, you.
Apparently I have 67 viruses, and my computer will crash, deteriorate, burn, hang itself, implode, explode, get the dementor's kiss, and slaughter the entire Uchiha Clan as well as the herons of the Serenes Forest if I don't download this Malware Protection. So I tried that, and all of a sudden there are naked women all over the desktop. (Undownloading and deleting.) That was a dumb move, but the anti-virus looked pretty legit. By the way, eighth graders who dress up like sluts at the movies aren't cool. Just saying.