To change the computer name or domain membership, follow these steps:
Click Start, point to Settings, click Control Panel, and then double-click System.
On the Network Identification tab, click Advanced.
If you want to change the computer name, type the new name you want in the New Computer Name box. If not, continue to the next step.
If you want to change the domain name, type the new domain name in the Domain box. If not, continue to the next step.
If you want to change the name of the DNS domain name, click More, and then type the name of the DNS domain in the DNS domain name of this computer box. If not, continue to the next step.NOTE: When you select the Change DNS domain name when domain membership changes check box, DNS domain name changes when you change to a new domain, but does not change if you change to use a workgroup.