Ok this isnt that bad! Ill try and give you a list of free/shareware tools that should get you back up and running. As always boot into safe mode with networking support.
Adaware - Full system scan - works well no question.
CWShredder - Scans for a list of know spyware not like a sys scan but more like a checklist scan. pretty good.
HiJackThis - Wicked for showing you whats booting up on boot. Better then msconfig for sure.
MSAntiSpyware - Some will give me 5#17 for this but in the right settings this guy does a decent job. Mainly if you can just roll it out on to a network with LEGAL WINDOWS COPYS! (they should be anyways you pir8s!)
The Cleaner - Really more for trojans but it will pick up alot of irc bots and other shady tojans that you might not know you have like dsnx i.e. 847943879843784975.exe that dont really do anything... or do they?
Avast - I love this software because its got email/p2p/live protection, its also got web protection that will scan inside archived files (zip/rar/tar) so if you goto www.freecracks.il
and theres a bot in theyer rar file itll be blocked or warned.
AV- Theres lots I just like avast, its my fav of the free ones right there but theres a number, just get one with up to date definitions and you should be good. That will kill like 90% of them.
Safe Your Self!
FireFox - Everyone says that putting on FireFox(FF) will save you. Right now that holds pretty true. From all the security sites and new sites, with all the users switching to FF soon FF wont save you. But right now Ill provide that extra little layer of comfort that should cut down a lot of hte internets crap.
Hope this helps ya, If not reply and Ill help ya out some more.