I found this thread - hurrah! It exactly matches my problem: "No window opens when Firefox is clicked on, but runs in the background for each time it is clicked. Cursor repeatedly flickers or spins after opening.". . . (Exactly my problem, but how do I fix it?) CoNiGMa 4/27/20, 11:43 AM My problem started after being on a Betfair portal site and selecting Firefox as my browser, declining to select Internet Explorer - since then my cursor has speen spinning - i looked at Task Manager to see constant activity and two copies of Firefox, so I entered "Cursor spinning" on the Help - and found the thread above. Great! But how do I resolve the problem, I'm not an IT person and I don't know where to enter any "kill..." commands, whatever they are. Your help would be greatly appreciated!!