If Firefox windows open off screen or are too large to use, you may need to reset Firefox's controls and toolbars.

1. Close down Firefox completely. If you cannot close Firefox due to the window size or position, restart your computer.
2. In Windows, click Start, open the All Programs list, and navigate to the Mozilla Firefox folder. In the Mozilla Firefox folder, select Mozilla Firefox (Safe Mode).Hold down the option key, as you start Firefox.Go to your Terminal and run:

   firefox -safe-mode

   You may need to specify the Firefox installation path (e.g. /usr/lib/firefox-3.5). Firefox should start up with a Firefox Safe Mode dialog.
   
   Note: You can also start Firefox in Safe Mode by clicking Start, selecting Run (or use the Start Search box in Windows 7 and Vista) and then entering the following in the text field:
   

   firefox -safe-mode

3. Check mark Reset toolbars and controls.
   
   
   
4. Click Make Changes and Restart to restart Firefox.
   
   
   
   
   
   

The Firefox window should appear at a sensible size and position.