Let's try two things. '''Try the Firefox SafeMode''' to see how it works there. <br /> ''A troubleshooting mode, which disables most Add-ons.'' <br /> [https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode#w_safe-mode-window_2 Troubleshoot Firefox issues using Firefox SafeMode] When in Safe Mode... <br /> * The status of plug-ins is not affected. * Custom preferences are not affected. * All extensions are disabled. * The default theme is used, without a persona. * userChrome.css and userContent.css are ignored. * The default toolbar layout is used. * The JIT Javascript compiler is disabled. * Hardware acceleration is disabled. * You can open the Firefox 15.0+ SafeMode by holding the '''Shft''' key when you use the Firefox desktop or Start menu shortcut. * Or use the Help menu item, click on '''Restart with Add-ons Disabled...''' while Firefox is running. ''To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before using the Firefox shortcut (without the Shft key) to open it again.'' '''''If it is good in the Firefox SafeMode''''', your problem is probably caused by an extension, and you need to figure out which one. <br /> http://support.mozilla.com/en-US/kb/troubleshooting+extensions+and+themes <br /> Or it might be caused by Hardware Acceleration. <br /> https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration ----- If that doesn't solve your problem, you may have picked up some Malware. Install, update, and run these programs in this order. They are listed in order of efficacy.<br />'''''(Not all programs detect the same Malware, so you may need to run them all to solve your problem.)''''' <br />These programs are all free for personal use, but some have limited functionality in the "free mode" - but those are features you really don't need to find and remove the problem that you have.<br /> ''Note: If your Malware infection is bad enough and you are mis-directed to URL's other than what is posted, you may have to use a different PC to download these programs and use a USB stick to transfer them to the afflicted PC.'' Malwarebytes' Anti-Malware - [http://www.malwarebytes.org/mbam.php] <br /> SuperAntispyware - [http://www.superantispyware.com/] <br /> AdAware - [http://www.lavasoftusa.com/software/adaware/] <br /> Spybot Search & Destroy - [http://www.safer-networking.org/en/index.html] <br /> Windows Defender: Home Page - [http://windows.microsoft.com/en-US/windows7/products/features/windows-defender]<br /> ------ ''When you figure out what is causing that, please let us know. It might help other user's who have that problem.''