A customer just brought me an older HP 6550b Probook with a Core i3. It had done it's 21H1 upgrade and was locked at .89 Ghz. Incredibly slow. I removed the 21H1 upgrade and all is back to normal. I also notice that I cannot delay updates. "Pause limit has been reached". I need to install current updates before I can pause again and the only update showing is 21H1 which causes problems. Hmmm..... I'm just sitting down to do my "due diligence" with Google and see what HP and others have to say.