In this video i will show you how to join an existing computer to a domain.

1. From Windows XP Professional, select Start, right-click My Computer, and select Properties.
2. From the System Properties dialog box, select the Computer Name tab, then click the Network ID button.
3. The Network Identification Wizard will start. Click the Next button.
4. In the Connecting To The Network dialog box, verify that the This Computer Is Part Of A Business Network, And I Use It To Connect To Other Computers At Work option is selected and click the Next button.
5. The next question will ask what kind of network you use. Verify that the My Company Uses A Network With A Domain option is selected and click the Next button.
6. The Network Information dialog box will appear. Click the Next button.
7. The User Account And Domain Information dialog box will appear. For User Name, specify Administrator, and for Password and Domain, specify the options that are valid on your network. Since this is a simulated environment, you can use any password or domain name. Then click the Next button. Click Yes to continue.
8. The User Account dialog box will appear. Click the Do Not Add A User At This Time option and click the Next button.
9. The Completing The Network Identification Wizard dialog box will appear. Click the Finish button.
10. The Computer Name Changes dialog box will appear, notifying you that you need to restart the computer for the changes to take effect.