Zone Alarm is a personal firewall security package that can be used to block malicious activity.

Zone Alarm is an optional installation for those computers that are wired to a firewall, but is mandatory for laptops and sites using wireless LAN connections.

License: The basic version of ZoneAlarm is free for individual and not-for-profit charitable entity use (excluding governmental entities and educational institutions). check the site at http://www.zonelabs.com for more information.

The Pro version allows you to have more selective control over functionality.

If you are having trouble with web browsing due to sites like Gator or X10, Zone Alarm can be used to block the intruder.