The Registry value entries that control the logon sequence for starting Windows NT are found under the following Registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
AutoAdminLogon REG_SZ 0 or 1
Specifies automatic logon if this value is 1. You must also add the value entry DefaultPassword with a value for the user listed under DefaultUserName for automatic logon to work.
When AutoAdminLogon is used, Windows NT automatically logs on the specified user when the system is started, bypassing the CTRL+ALT+DEL logon dialog box.
DefaultPassword REG_SZ Password
Specifies the password for the user listed under DefaultUserName. Used during automatic logon.
DefaultUserName REG_SZ Username
Specifies the name of the last successfully logged on user. If values are defined for DefaultPassword and AutoAdminLogon, this is the user who is logged on by default during automatic logon.