Windows 10: User - how to stop a user from accessing private files of the Administrator user?

Can't find how to stop one extra user from accessing files of Administrator user.How can this be done?The other user is not family and does not have an email address, it is a user I can user to lock the PC when i'm not there, but still have access to it.Should I set up a family user?Thanks

:)

 

user files are accessible to all users

I am setting up a new computer. I am set up as administrator (local account) and I have added my kids as Other users (local account-not administrator). (I do not want to set them up as a Microsoft accounts).

The new computer has one (small) hard drive for storing the operating system and a large hard drive for storing data. All user accounts were set up on the small drive. I changed all the user accounts to the other drive by following steps on Microsoft to
move the folders under folder properties, doing it folder by folder-documents, then music, then pictures, etc. for each user. All the files in the various user accounts are synced (with a local copy) with Dropbox.

That seemed to work except that all of user files are accessible to all users. If you look on the folder properties for the folder, they all say they aren't shared but they are.

I am trying to fix this by going in to folder properties and changing the security settings. Under the security settings, the following groups have access to my administrator folder: Authenticated Users, SYSTEM, [my user account], Administrators, Users.
Under Advanced, I disabled inheritance for the user account folder. Then I delete the access for user. That blocked access for other users to my some of my user folders but not others. (I primarily care about access to my files.)

Any suggestions for fixing this?

 

Removing a "hidden" user and user files

Thanks for your patience. I was able with "Net User" to remove the left over user. It no longer appears when I invoke Net User.

Now for the user's folder which remains behind. After performing the series of steps that you suggested, I attempted to delete this folder. The result again was an error message about permission


"Administrators" appears on the list in the list of advanced security.

 

Current active users that are friends

The other reason I suggested this is that users can add characters to their username that are not alphanumeric (e.g. user*). This confuses things somewhat when looking at the list.