Site passwords are lost after each reboot since a recent windows 10 update.

Regret to say that did not work for me.  Great to hear that is solved your problem.  Will keep trying to find a solution.

I only had the one task and that was HP Laserjet printer.  Have disabled it but it was created the same day as the Windows update.  Will see how that goes.

I've read this entire thread, from beginning to end.

It is clear that: (a) Microsoft's 2004 Win 10 version is junk; (b) Microsoft's engineers knew - or should have known - that the 2004 Win 10 version was junk; (c) Microsoft's contempt for its users (victims) is unlimited.

I've lost passwords, bookmarks, etc. I will try to go back to the prior version of Win 10.

Those, at Microsoft, who have inflicted on us this horrendous "upgrade" need to be weighed-down with anchor chain, taken out beyond the 1,000 fathom line, and dropped into the Pacific.

There is no other way to be sure that such depraved persons no longer will be able to make and issue catastrophically defective products and misrepresent them as "upgrades".

Microsoft's engineers are a modern version of the 19th Century "snake oil" sellers, who misrepresented their concoctions as "medicine". By so doing, they injured many.

Lesson learned. Wait a full year after an MS "upgrade" offer and Google before installing it, to make sure that it, too, is not poisonous.

Did you do a clean install of Windows or retain your settings?

If it was a clean install then for myself that would be no walk in the park after it was reinstalled.

Your issue is exactly what I am experiencing.  Did you find a solution?

Yes. Reinstall Windows. Fairly painless, gets rid of lots old leftover crud. Machine now working perfectly. 

Instead of reinstalling windows all you have to do is create a new admin user profile and it will work.

Not necessarily. I did that when this first happened. As it recurred, a new install made sense. If it's a Windows problem, potentially introduced by something in 2004 clashing with something from previous updates, or software I installed, or my brief foray into the Insider Ring, I'd rather have a clean build. 

It's not exactly hard to do, these days. I'd go so far as to say it was a walk in the park.