Windows 10: My pc's have been taken over - cannot remove unauthorized users

I hope someone can help me - I have two HP pcs running Win 10 and, in short, they have both as well as my Android phone been taken over by some unauthorized users who are using developer options to gain access to my machines. I've tried reinstalling, resetting, etc...several times on all devices and they still always find their way back almost instantly to any device I own. They have rewritten my firewalls/added their own rules, reset my accounts to where I rarely have access to anything anymore, and the list goes on and on. It's as bad as you can get.I think I need help reinstsalling/resett

:)

 

Unauthorized user has installed OS on my computer & taken control...but is being "nice" about it?!?

I just reinstalled Win 10 after a complete data wipe and an unauthorized user has already taken control. They have saved my installation and installed a complete build of Windows 10 and appear to be content just leaving it there for me! It's a nice build
(I think from Kodi), fully automated it seems with event handling, etc How do I get rid of this unauthorized user(s)? It seems like they are trying to help me but that is a rather odd way! Im a newbie to windows and networking, etc. Ive discovered ways they
are gaining access (remote network adapters, ie).

Just dont know where to start but tried command prompt to remove users, get error. I can inactivate them but not remove. Help please!

 

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.

 

Remove account

I suggest you backup your personalized files first before removing the account.
To delete an account, follow these steps:

1. Press WIN + X keys and click Command Prompt (Admin) from the menu.
2. Type the following command and press Enter. Replace test with the name of your sister's account. Code: