Firefox keeps opening many tabs or windows.For more information on problems with Facebook, see Fix problems with Facebook games, chat and more. For more information, see Firefox won't start - find solutions.
For more information, see Troubleshoot Firefox crashes (closing or quitting unexpectedly) and Firefox hangs or is not responding - How to fix. For more information, see Websites show a spinning wheel and never finish loading and Firefox cannot load certain websites. For more information on setting your home page, see How to set the home page.
For more information, see What to do when searches take you to the wrong search website. For more information on blocking popups, see Pop-up blocker settings, exceptions and troubleshooting. Symptoms are various and depend on the malware, but if you have one or several of these behaviors, you may have malware installed on your computer. How do I know that my Firefox problem is a result of malware?