FIREFOX help

by any chance are you running Zone Alarm?

There is a compatiblity issue with a recent XP update and Zone Alarm, if this is the case, just go to your Zone Alarm control panel and go to firewall settings, move the Internet zone slider from maximum to medium, you will be able to access the internet then. go to Zone Alarm website and download latest version of your engine:

ZoneAlarm Internet Security Suite

ZoneAlarm Pro

ZoneAlarm Antivirus

ZoneAlarm Anti-Spyware

ZoneAlarm Basic Firewall

Here is the link to the Microsoft advisory: http://download.zonealarm.com/bin/free/pressReleases/2008/LossOfInternetAccessIssue.html

Hope this helps