Millions of people around the world use ZoneAlarm Free Firewall. Our free software blocks hackers and prevents viruses & spyware from stealing your personal data and sending it out to the Internet. Also, works great with any antivirus software
Microsoft Windows Vista SP1 or SP2 Business / Home Premium / Ultimate:32-bit / 64-bit, 2 GB RAM2 GHz or faster processor100MB of available hard-disk spaceMicrosoft Windows, XP SP2 or SP3 Home / Professional32-bit, 1GB RAM1 GHz or faster processor100MB of available hard-disk spaceAdditional feature-level requirements:
Additional requirements are available for browser security, spam filtering, hard-drive encryption, and parental controls.