FREE ONLINE VIRUS SCAN

No antivirus will catch all viruses, and not all firewalls will catch all intrusions, so sometimes you will need to do an online scan to clean out or at least find bad files.

Kasper Sky Online Scan will scan a particular file of your choice.

Panda Antivirus Free Online Scan. God Bless America and Panda for this wonderful free scan that will find viruses and trojans and clean all your files; I know this one really works.  HIGHLY RECOMMEND

Spygate Online Port Scan to test your system.

WindowSecurity will do an online scan of particular drives and let you decided if you want to delete it or not.