For actual domain administrator account resets, Microsoft’s official (though paid) solution is the only fully supported method. However, in a non-production or lab environment, you can use the same free tools if the server is not replicating with other domain controllers.
Remember: with great power comes great responsibility. Use these tools only on servers you own or have explicit permission to recover. Always back up critical data before manipulating the SAM registry. windows server 2016 password reset tool free
copy d:\windows\system32\cmd.exe d:\windows\system32\utilman.exe : Remove the media and restart the server normally. For actual domain administrator account resets