To change the computer name, to join a domain, or to add a computer description for a Windows XP-based computer, use the Computer Name tab in the System Properties dialog box. To locate this tab, use one of the following methods:
1. Click Start--> right-click My Computer--> and then click Properties.
2. Click Start--> click Run--> type sysdm.cpl--> and then click OK.
3. Click Start--> click Control Panel--> double-click Performance and Maintenance--> and then click System.
4. Select Computer Name tab--> and click Change to change computer name and workgroup.
5. In this Computer Name Changes window--> key in Computer Name and also Workgroup.
Note: Please make sure computer name is unique in your network and not more then 15 characters. Avoid using these characters for naming your computer: * “ . , @ /
6. System will prompt you to restart computer--> Click OK and restart your computer for the changes to take effect.