You don't have get Norton... I Use AVG 7.5 and Windows SP2's Firewall... I'm clean. :P
You know why? Cus everyday my AVG runs a full scan, and updates itself, plus I have Ad-Aware personal a must get program to remove trijans, spyware, etc...etc...
I recomand you to download Ad-Aware and to run a full scan with your antivirus software... maybe updating it first
Tell me how did it go...