Hi Troepp. II'm Greg, awarded MVP for eleven years, Volunteer Moderator, and Independent Advisor here to help you until this is resolved.
Is your friend's account a work or school account that would have Group Policy set by a System Administrator? Usually these are connected to a domain.
1) If you don't have a Professional version where Group Policy has been set to manage settings then it could be caused by your antivirus. So I'd first uninstall your Anti-virus to try running with built-in Defender which always offers best Windows performance with least issues, and is from Microsoft who knows how to protect their OS best. To make sure it's fully removed run the uninstaller for your AV here;
https://www.bitdefender.com/consumer/support/an...
2) See other fixes for this specific error here:
https://www.xtremerain.com/some-settings-are-ma...
https://superuser.com/questions/947755/some-set...
https://www.kapilarya.com/some-settings-are-man...
https://blog.pcrisk.com/windows/12584-some-sett...
https://windowsreport.com/some-settings-are-man...
https://answers.microsoft.com/en-us/windows/for...
https://superuser.com/questions/1281524/windows...
https://www.minitool.com/news/some-settings-are...
3) Check if there is a Work or School account listed in Settings > Accounts > Access Work & School, if so highlight it and choose Disconnect. Restart PC. Does the error go away?
4) This can be caused by Account corruption. Test for account corruption by creating a new Local Account in Settings > Accounts > Family & Other People:
http://www.howtogeek.com/226540/how-to-create-a...
Make it an Admin Account:
https://www.windowscentral.com/how-change-user-...
Sign into it, see if the same problem exists. If not move your files over from the old account, test all programs run correctly or reinstall.
Then when ready you can delete the old in the same place as above, and convert the new account to your MS account if desired:
https://www.tenforums.com/tutorials/5375-switch...
If you want to try to reform the broken account, you can use the new Admin account to run a Repair Install which reinstalls WIndows while keeping your files, programs and most settings in place, by installing the Media Creation Tool from this link
http://windows.microsoft.com/en-us/windows-10/m..., open the tool and choose Upgrade This PC Now. This will solve most problems and also bring it up to the latest version which you need anyway and by the most stable method.
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But remember that Factory or Upgrade installs are inferior installs which most enthusiasts won't even run because they'd expect endless issues. Consider doing the Clean Install in this link which compiles the best possible install that will stay that way as long as you stick with the tools and methods given:
http://answers.microsoft.com/en-us/windows/wiki...
There is also an automated Refresh that reinstalls WIndows while shedding corrupting factory bloatware, saves your files, but doesn't clear the drive to get it cleanest:
https://www.howtogeek.com/265054/how-to-easily-...
I hope this helps. Feel free to ask back any questions and keep me posted. If you'll wait to rate whether my post helped you, I will keep working with you until it's resolved.
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