Use the Local Group Policy Editor to disable the administrator privileges. Here are some steps you can try:
- Press Windows and R keys, then type in the text box and press Enter key to open the Local Group Policy Editor.gpedit.msc
- In the Local Group Policy Editor, click Computer Configuration - Windows Settings - Security Settings - Local Policies - Security Options.
- In the right pane, find the policy named “Accounts: Administrator account status” and double-click on it. In the pop-up window, select Disabled and click OK to save the changes.
- Restart your personal computer and check if the message is gone.