How to enable automatic logon in Windows 2003 Advanced Server

Use Registry Editor (Regedt32.exe) to enable automatic logon

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

To enable automatic logon, follow these steps:

1. Start Regedt32.exe, and then locate the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
2. Using your account name and password, double-click the DefaultUserName entry, type your user name, and then click OK.
3. Double-click the DefaultDomainName entry, type the domain name, and then click OK.
4. Double-click the DefaultPassword entry, type your password, and then click OK.

   Note If the DefaultPassword value does not exist, follow these steps:

   1. Click Add Value on the Edit menu.
   2. In the Value Name box, type DefaultPassword, and then click REG_SZ for the Data Type
   3. Type your password in the String box, and then save your changes.

   Also, if no DefaultPassword string is specified, Windows automatically changes the value of the AutoAdminLogon key from 1 (true) to 0 (false), which disables the AutoAdminLogon feature.

5. Click Add Value on the Edit menu, enter AutoAdminLogon in the Value Name box, and then click REG_SZ for the Data Type.
6. Type 1 in the String box, and then save your changes.
7. Quit Regedt32.
8. Click Start, click Shutdown, and then click OK to turn off your computer.
9. Restart your computer and Windows. You are now able to log on automatically.

NOTE: To bypass the AutoAdminLogon process, and to log on as a different user, hold down the SHIFT key after you log off or after Windows restarts.

Src: http://support.microsoft.com/kb/310584