Wow - really looks like a bug then. But other than the search not working, it's seemingly a non-destructive problem?

That's funny - it's interesting that that it gets the "max speed" right, but the current speed so badly wrong.

My Win 10 TaskMgr is also getting my actual cpu speed wrong, but in the opposite...

Now that build 10586 has gone public I've finally switched my main desktop PC over to 10 Pro from Windows 7. I took the safe route and did an upgrade install first, then a reset, and I'm starting to...

Well that's the thing - I would suspect that you just happen to be seeing the symptoms first with regedit, but whatever's wrong will eventually cause more widespread problems.

Case in point: I...

Just a thought - have you taken a good look through the system event log (Event Viewer -> Windows Logs ->System) to see if there are any clues there ?