A user name is the name with which you log in to Community Server and is your identifier within the community. Whenever you are identified with a post or any kind of activity, other users will see your user name.
Community Server allows you to determine how you want your identifying user name to display.
Procedure
1. Click Edit profile on your Dashboard page.
The Edit Your Profile page opens with the Profile Options tab active.
2. Scroll down the Profile Options tab to the Name data field in the Common Profile Options section.
3. Enter your user name in the Name data field.
4. Click Save.