From the developer: PC DoorGuard is a full-featured extensive and thorough intrusion scanner that scans any media on your PC for backdoors and trojan horses. PDG easily removes any found trojan with a click of a button. PDG monitors your system to prevent further infection, using weekly updated trojan database consisting of more than 37500 entries. Active e-mail Scan, full drive scan on demand, monitoring ports,- all this provides secure environment for your PC.