Why won't webpages load unless I move the mouse?

Episode 1714
Walter fromWalter has an old Dell i7 laptop that he loaned to a friend. But lately, the Firefox browser won't load a page until you move a mouse and the page pops up. What is that all about? Leo says it sounds like a bug in Firefox that is waiting for an input. It's called a "signal event loop." It may be a failed install of Windows 10 is likely the culprit. So back up the data, wipe the drive, and reinstall Windows 10. That should solve the issue.