Follow this two-step process to delete a user profile in Windows Server 2016 in workgroup mode:
- Go to advanced system settings (sysdm.cpl), advanced tab, click on settings in the user profiles box (middle of screen), under “profiles stored on this computer” click on the user profile you want to delete and press Delete.
- Then go into Computer Management, Local Users and Groups, Local Users, and select the user you want to delete and delete it.
- Reboot and confirm that user no longer exists in User Profiles, Computer Mgt, and c:\users.
- Note: If you only delete the username in Computer Management, the user will continue to shot up in advanced system settings in user profiles (label changed to unknown) and the c:\users\username folder should still exist. If you only delete the username in User Profiles, the c:\users folder should be gone but the user account will still show up in Computer Management. This is why you should perform both steps to delete User Profile in Advanced System Settings first, then User account in Computer Management.
See this link from Microsoft: https://support.microsoft.com/en-us/help/2462308/delete-a-user-profile-in-windows-server-2008-and-later