I have Windows 7 64-bit. Firefox won't start. I updated to version 44.0 and now it's broken. When I double-click the icon I get the spinning circle, I can confirm that the firefox.exe process starts running in Windows Task Manager, but I never see the Firefox window on my desktop. Doesn't matter how many times I end the Process Tree or restart the computer. I never see the Firefox window. I tried hitting "Windows key + R" and typing "firefox /safe", but I got the same result: spinning wheel, process starts, but I never see any Firefox windows. I also tried running Firefox as admin by "right-click", "run as admin." Same result. I also tried uninstalling Firefox version 44.0, deleting the program folder from "c:\program files", deleting the Mozilla folder in "c:\users\username\appdata\Roaming", deleting the Mozilla folder in "c:\users\username\appdata\Local." I then reinstalled Firefox 44.0 and experienced the same issue. Finally I tried uninstalling Firefox 44.0 again, deleting program folder again, but this time I installed the previous version "43.0.4." Guess what, it started without any issues. Worked perfectly. So then I ran the auto-update to version 44.0 again and the program stopped working. Great job guys!