See this [https://support.mozilla.org/en-US/kb/Pop-up%20blocker?s=popup&r=0&e=es&as=s Popup Blocker] ''Note : Please mark the problem as "Solved" if any reply helped you out. ''

Also see this article for more info on Pop-ups -> http://kb.mozillazine.org/Popups_not_blocked You can use the following add-on/extension for Blocking Ads & Pop-ups: -> Adblock Plus 2.0.3 * https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/ * Subscribe to its Filter lists: ** http://adblockplus.org/en/getting_started ** http://adblockplus.org/en/subscriptions Check and tell if its working.

Also, try scanning your computer for malware, which can sometimes cause pop-ups: Download and Install MalwareBytes Anti-Malware, run a full Scan. [http://www.malwarebytes.org/ http://www.malwarebytes.org/] Download and Run TDSSKiller [http://support.kaspersky.com/faq/?qid=208283363 http://support.kaspersky.com/faq/?qid=208283363] Download and Install Microsoft Security Essentials [http://windows.microsoft.com/en-US/windows/products/security-essentials http://windows.microsoft.com/en-US/windows/products/security-essentials] (not an official endorsement, but I personally recommend MSE as an awesome permanent anti-virus) Double check for all Windows Updates.