This value has only two legal values, according to Microsoft: 0 and 1. 0 disables automatic logon of the account stored, and 1 enables it.
However, if you set this key to 2, it will enable automatic logon and disable Ctrl-Alt-Del. For this to work you will have to set the "DefaultUserName" and "DefaultPassword" keys to the username to automatically logon. This means storing the password in the registry in cleartext, so if you cringe from the idea of doing that, don't use this extra tip.
Please note, one disadvantage to using the above method is that it disables too many security features at once. Another way to disable the need to press Ctrl-Alt-Del from the startup screen is to edit the Registry and add a REG_DWORD value named DisableCAD REG_DWORD to the following registry key:
Set DisableCAD to 1. To reset Ctrl-Alt-Del behavior, either delete the key entirely or set it to zero.
(My thanks to SearchWin2000.com member Stan Balog for this additional information.)
This was first published in April 2004