System Restore is probably the thing to try first. It’s really not that difficult:
http://www.bleepingcomputer.com/tutorials/tutorial56.html
Spybot and Ad-Aware are more for spyware/adware infections; a-Squared, AVG Anti-spyware and CureIT! are more targeted at this sort of Trojan.
It really would be a good idea to scan with the Secunia scanner to check for the vulnerable application that might’ve allowed a drive-by install like this.