SBS 2003 Problem

I’m a novice concerning SBS 2003. It came installed on a new server and I was asked to configure it. I did follow the wizards but after configuring just the internet connection I decided to change the name of the server using the Name Tab under properties of My Computer. Now I see references to both server names on the machine. Can I change the name back to the orginal (using the same method)?

Would this cause an error in configuring Exchange? Each time the wizard ends with an error and email not being able to be setup.

The machine has only one nic so I don’t get the firewall configured by SBS. The router handles it.