I've scrubbed the Registry three times. Twice with RegSupreme Pro -- which I don't think actually works unless you pay for it. After scrubbing once, I restarted and ran it again -- and got the same damned results!
I then got Wise Registry Cleaner and ran that. It fixed things.
Then I also got Wise Disk Cleaner and ran that.
Then I got Auslogics Disk Defrag and ran it overnight to thoroughly defrag the drive.
Then, this morning, I ran Wise Disk Cleaner a second time.
Then I went to YouTube.
YouTube still stutters!! (And yes, I'm waiting for video to preload!)
Now I go in and start ripping out those damned Windows Updates.
In the meantime, I'll put up a YouTube vid to keep you amused.