How to Disable the "Logon Using Dial-Up Networking" Option

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base: This article explains how to disable the Logon Using Dial-Up Networking checkbox at the logon prompt on your Windows NT computer. This option normally is available on the logon dialog box and permits you to dial into your logon server to authenticate your user account.

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk. To configure this option so that it is not available, use the following steps to edit the registry:

1. Start Registry Editor, and then click the following subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion \Winlogon
2. On the Edit menu, click Add Value, and then type the following information:
   Value Name: RASDisable
   Data Type: REG_SZ
   Value: 0 or 1

If you are running Windows NT, update your Emergency Repair Disk (ERD).

Note: After you add this value, the Logon Using Dial-up Networking check box is not available.