Secunia PSI

Secunia PSI (Personal Software Inspector) is a free security tool designed to detect vulnerable and out-dated programs and plug-ins that expose your PC to attacks. Attacks exploiting vulnerable programs and plug-ins are rarely blocked by traditional anti-virus programs. Secunia PSI checks only the machine it is running on, while its commercial sibling Secunia CSI (Corporate Software Inspector) scans multiple machines on a network.