Unable to open a second Window
I recently upgraded my Firewall to Zone Alarm Pro and added their Anti-virus as well. Since I've done that I can't open a second Firefox Window. Additional tabs open fine, and any other browser will open a second Window without a problem, but I prefer to use Firefox. I tried reinstalling Firefox 3.6.8 but that didn't solve it.
Opaite Mbohovái (1)
Try to disable the ZoneAlarm Toolbar extension.
Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).
See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems