I think I have a virus

[fees]

Ok, so I woke up today and hop on my computer, and when I do I notice that its acting strangely. I had an AIM chat winow open and it was typing the letter z over and over again, I looked at the z key.. nothing was wrong with it. Then it started to type some other random keys, quickly... at this point I just closed the window. I then tried to open IE and it wouldn't let me, every time I would go to open IE it would open another folder on my desktop instead. At this point it just seems like there was something that had access to my computer at the same time I did, but it didn't seem to have a purpose, everything it was doing was seemingly random, but it was stealing control from me and doing all sorts of clicking and typing of random letters.

So basically, I was like [censored] ! and hopped on my laptop to change all my poker passwords, but right now I have my comp all screwed up.

I tried to figure out wtf this was (I assumed it was something from yesterday) .. so I've been going over it, the questionable stuff I did was: click on that guy who spammed like half the forums with "my bodog check bounced"... I clicked it- it took forever so i closed it, uhm i downloaded skype but that was about a week ago, hrm...

man actually I can't think of anything else, yesteray was all poker, aim, skype, and 2p2.. I didnt really use anything else.. itunes maybe

In any event what are my options to do with this comp now that its got some virus or something ?

Thanks