https://www.switchfast.com/blog/solved-windows-...
I already wrote out how to access the Command Prompt from bootable media, and here is how to access it from the onboard Repair Mode in Windows 10: https://www.tenforums.com/tutorials/2294-advanc...
You can also try Taking Ownership using this handy right click shortcut which installs a Take Ownership shortcut to your right click menu to use in cases like this on files and folders which won't cooperate:
https://www.askvg.com/add-take-ownership-option.... The only warning is to not use it on C:\Windows folder files as this will compromise security.
Did you do this step yet to confirm account corruption is the issue:
Test for account corruption by creating a new Admin Local Account in Settings > Accounts > Family & Other People > Other People, sign into it, see if problem persists:
http://www.howtogeek.com/226540/how-to-create-a...
http://www.windowscentral.com/how-change-user-a...
If you're blocked from creating a new account, try enabling the built=in hidden Administrator account used only in emergencies, by one of these methods:
https://www.tenforums.com/tutorials/2969-enable... then sign into it leaving the password box blank, to create the new account as above.
If the problem goes away move your files over, test all programs run correctly or reinstall.
Then when ready you can delete the old account in the same place as above, and convert the new account to your MS account if desired:
https://www.tenforums.com/tutorials/5464-delete...
https://www.tenforums.com/tutorials/5375-switch...
You can also try repairing the account or install using a fresh set of installation files running a Repair Install as shown here: https://www.yourwindowsguide.com/2016/06/how-to...
I hope this helps. Feel free to ask back any questions and keep me posted. If you will wait to choose if I resolved your problem, I will keep working with you until it's resolved.
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Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.