Hello. You may be having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal? Whenever you have a problem with Firefox, whatever it is, you should make sure it's not coming from one of your installed add-ons, be it an extension, a theme or a plugin. To do that easily and cleanly, run Firefox in [http://support.mozilla.com/en-US/kb/Safe+Mode safe mode] and select ''Disable all add-ons''. If the problem disappears, you know it's from an add-on. Disable them all in normal mode, and enable them one at a time until you find the source of the problem. See [http://support.mozilla.com/en-US/kb/Troubleshooting+extensions+and+themes this article] for information about troubleshooting extensions and theme. You can troubleshoot plugins the same way. If you want support for one of your add-ons, you'll need to contact its author. As for making sure Firefox is not running, Window's task manager is very bad, in that the tab that is open by default is the "Applications" tab, and not the "Processes" tab, basically, the "Processes" tab is where all programs that are running are listed. The "Applications" tab only lists the windows that are accessible through your taskbar (which makes it essentially worthless, especially since "terminating" the applications there is basically like clicking the "X" on the windows themselves). Always use the "Processes" tab to know what is running and what is not.