Since Facebook Messenger for Windows shut down on March 3, 2014, my Firefox browser won't stop opening new tabs with the same message. "We're sorry, but we can no longer support Facebook Messenger for Windows, and it will stop working on March 3, 2014. We really appreciate you using Messenger to reach your friends, and we want to make sure you know that you can keep chatting and view all your messages on http://www.facebook.com. Learn more." I have a Dell laptop running Windows 7.