Step 1: Delete the value in DefaultUserName
Step 2: Change the value in DefaultDomain Name
Exit the Registry Editor
Adjust as necessary to your specific platform. The next user login displays a blank login name and the familiar domain.
The Registry method is fast and elegant. Alternatively, a crude and simple method is: a) logoff as Administrator; b) logon as yourself in the standard domain; and then c) logoff. The net effect is similar.