This really isn't solved. It is a bug that hasn't been fixed in Windows 10. I started having the problems that all you have mentioned then all of a sudden I started getting more errors when I tried to open programs. I started getting errors saying that I don't have access to the folder where the program is installed. It seems to almost gets worse as time goes on. I've tried all the suggested remedies but once you reboot, everything reverts back. The first thing I noticed was that I always shut off the tap, scroll and resizing function on my touch pad. Each time my machine restarts, I have to go back in and shut those features off again. It seems like nothing is getting saved once a machine reboots. I can't even convert some of my music files from m4a to mp3 because I get an error saying they are protected even though they aren't. My iTunes won't launch because it says it is installed in a folder I no longer have access to.
There is a hidden Administrator account in Windows 10 but it is disabled from view. You can enable it by calling up a Command Prompt window with Administrative privilege. At the prompt you type:
net user administrator /active:yes
When you restart, you'll see that you now can login as the TRUE administrator. Some have suggested the problem is caused by the Microsoft OneDrive. I've even disabled that and still have the problem.
Microsoft should have done a lot more testing on this pile of junk before they forced down everyone's throat. I can't believe this never cropped up anywhere in their beta tests.