Prevx is Host Intrusion Prevention System software, probably the best and easiest of this type of software. Free until it finds an exploit and then lets you cure for 28 days after it finds something OR you can continue using it free as an IDS. This will secure you from zero day exploits/new malware out there that doesn't have a signature. It also acts as an outbound firewall. GOOD STUFF!!! IDS/HIPS software is usually very complicated to use because you have to know your computer 100%, but this software is easy as pie as it scans your computer and makes a database of applications/processes and alerts you to malicious changes. Many people use this as their sole security software because it's so powerful. I'm testing it currently.