ATTN: Computer Geeks (anulien etc)

Ok so I came home drunk last night and recieved an IM last night with a link from a friend saying something like "www.myspace.com/pic/345345 is this u?" so I clicked on it, downloaded it, and now I have some funky virus. Whenever I get on aim it sends that same message to everyone on my buddy list every minute or so.... what is the easiest way to get rid of this crap?