Firefox is my default browser on my desktop Windows 10. Until a few days ago all was great. But now when I turn my computer on and Firefox opens, things go very slowly. Opening a new window (tab) can take up to a minute. If I get 3/4 windows open, moving from one to another can take ages. Eventually, after about five minutes, everything is as it should be, and I can do everything at the usual great speed. But if I am away from the computer for an hour or so and then return to it, everything is ridiculously slow again. After about five minutes, it's flying again! Once it gets going again, things are so good and fast I can't believe there is a major problem. I have done a Refresh of Firefox, but no joy. I have turned the computer on/off/on at the mains, but no joy. I don't want to do an Uninstall/Install unless really necessary. I have 8GB of Ram, and loads of space on the C drive. But I am NOT tech savvy at all. When I go to Task Manager, it can show up to a dozen processes for Firefox. Is that normal? If I have only Firefox open, Memory shows at 50%. Is that normal? I would be grateful for any ideas. But I repeat, I am tech useless, so I need everything spelled out in the most basic English. I look forward to hearing from somebody! Thanks.