Just as a precaution, I'd go to an anti-virus site and let them do a complete scan of your system first.
IMO, BitDefender and Kaspersky are two of the best antivir programs.
A lot of us here run XP w/SP2 and Hal6 without incident.
BitDefender also checks for rootkits (one of the latest forms of malware circulating the net and it does an auto update of the latest virus definitions every 10 minutes).
Good luck!