Walter 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.
Walter is also having issues authenticating Windows 10. Leo says to go back to Windows 7. Authenticate that, and then upgrade to Windows 10. It will authenticate and you can move forward.