ok if you have win xp then its likely that you have blasterworm, and the best security solution for that is go to
http://www.kerio.com/kpf_download.html
after you connect to net dont browse around, just go straight to this site and download the firewall from here, while the firewall is being downloaded dont browse around leave it put the hands behind your head and leave them there until the download has been completed and then fallow the wizard and you have steal made firewall, thats all. i know aobut viruses. Fix all of your hackers, viruses, dailers, all of your problems at once, thats good advice from lucifer wouldnt you think so