Hello,

Go to the Mozilla Add-ons Web Page (There’s a lot of good stuff here) and look for a good add / pop-up blocker.

Also see: http://kb.mozillazine.org/Killing_pop-up_windows

Or to block pop ups completely here's how:

Disabling all popups in Firefox

 Type "about:config" (without the apostrophes) in the browser's address bar and hit the enter key.
 First time users need to confirm that they be careful on the next page.
 Type or paste "dom.popup_allowed_events" (without the apostrophes) into the search field.
 The value of the preference highlights all events that are allowed to spawn popups.
 Double-click the preference and "REMOVE" some or "ALL" of the items here. You can also add some if you want to do so.

note if you are successful, the next time a pop up comes you can set to disable notification from appearing.

Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• TDSSKiller - AntiRootkit Utility
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us!