You need to have user's first and last name in SharePoint User Profile Service Applictaion in order to see 'firstname lastname'.

Try modifying User Profile of your test user: add first and last name. Then log out and back in and you should see the correct name.

If that works, update other users as well (by setting up user profile synchronization).

You need to have user's first and last name in SharePoint User Profile Service Application in order to see 'firstname lastname'.

Try modifying User Profile of your test user: add first and last name. Then log out and back in and you should see the correct name.

If that works, update other users as well (by setting up user profile synchronization).