Clear the cache and the cookies from sites that cause problems. * "Clear the Cache": Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now" * "Remove the Cookies" from sites causing problems: Tools > Options > Privacy > Cookies: "Show Cookies" Start Firefox in [[Safe Mode]] to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes). * Don't make any changes on the Safe mode start window. See: * [[Troubleshooting extensions and themes]] ---- Other things that need your attention: Your above posted system details show outdated plugin(s) with known security and stability risks that you should update. # Shockwave Flash 10.0 r32 # Next Generation Java Plug-in 1.6.0_21 for Mozilla browsers Update the [[Managing the Flash plugin|Flash]] plugin to the latest version. *http://www.adobe.com/software/flash/about/ Update the [[Java]] plugin to the latest version. *http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform: Download JRE)