Try this Addon *https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/

Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of. '''remove the "Defualt Tab" addon.''' * https://support.mozilla.org/en-US/questions/957880 * malwaretips.com/blogs/default-tab-search-bar-removal/‎ You can try these free programs to scan for malware, which work with your existing antivirus software: * [http://www.microsoft.com/security/scanner/default.aspx Microsoft Safety Scanner] * [http://www.malwarebytes.org/products/malwarebytes_free/ MalwareBytes' Anti-Malware] * [http://support.kaspersky.com/faq/?qid=208283363 TDSSKiller - AntiRootkit Utility] * [http://www.surfright.nl/en/hitmanpro/ Hitman Pro] * [http://www.eset.com/us/online-scanner/ ESET Online Scanner] [http://windows.microsoft.com/MSE 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!

Try disabling ALL extensions on this tab: orange Firefox button (or Tools menu) > Add-ons > Extensions category Then restart Firefox using one of the links provided on that page. You can add back the extensions important to you one at a time as needed, and remove the ones that turn out to have no value to you. Any improvement?