How to Enable Computer Domain Option ?

To Start the Windows Service Editor:

1.   Click on the Start menu.

2.   In the Search programs and go to Run box (Win key + R), 

     then type services.msc.

3.   The below screen appears, with as per below & scroll down to "Workstation" (and double click this option), then Select the Startup type "Automatic" option then click "Start" and click Apply > OK or just OK.

4. Then check the computer Domain option & must be enable Domain option (as shown the below picture).