http://support.microsoft.com/default.aspx?scid=kb;EN-US;q234562
from the link above:
Preventing the Password Prompt in a Non-Domain System
1. In Control Panel, double-click Users and Passwords.
2. Click to clear the Users must enter a user name and password to use
this computer check box.
NOTE: This option does not appear on a system that is a member of a
domain.
3. Click the Advanced tab.
4. Click to clear the Require users to press Ctrl-Alt-Del before
logging on check box.
Automatic logon is not supported when you are logging on to a domain. You
will need to join a workgroup if you want to use the automatic logon
feature.
You can also turn on the automatic logon feature in all versions of the
Windows 2000 product family by editing the registry.
WARNING: This procedure will allow the user to log on automatically to the
domain. This could cause a serious security problem. Anyone booting this
system with this registry modification will be logged on to the system with
the user's security credentials. 1. Start Regedt32.exe and locate the
following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
NT\CurrentVersion\Winlogon
2. Establish your domain name, account name, and password, using the
values you would normally type when logging on. You should assign the
following values: DefaultDomainName, DefaultUserName, and DefaultPassword.
NOTE: The DefaultDomainName and DefaultUserName values may already
exist. The DefaultPassword value may not. If it does not, create it. To do
so: a. On the Edit menu, click Add Value.
b. In the Value Name box, type DefaultPassword.
c. In the Data Type box, click REG_SZ.
d. Click OK.
e. In the String Editor box, type your password. Click OK and
save your changes.
NOTE: If no DefaultPassword string is specified, Windows
automatically changes the value of the AutoAdminLogon key from 1 (true) to 0
(false). This disables the AutoAdminLogon feature. This behavior also occurs
if the DefaultPassword string is specified but the password is left blank or
null.
3. On the Edit menu, click Add Value. Type AutoAdminLogon in the Value
Name box. Click REG_SZ in the Data Type box. Enter 1 in the String box. Save
your changes.
4. Quit Regedt32.exe.
5. Shut down Windows and turn off the computer.
6. Restart your computer and Windows 2000. You should be able to log
on automatically now.
Note that this setting only applies to the first logon. To enforce
this setting for subsequent logoffs, the administrator must configure the
following setting:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon
Value: ForceAutoLogon
Type: REG_SZ
Data: 1
This is a by-design security feature. The resolution involves editing the
registry. Editing the registry is not supported.MORE INFORMATION
Windows 2000 Only
The process that is described in this article only applies to the first
logon. To enforce this setting for subsequent logons, the administrator must
set the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon
Value: ForceAutoLogon
Type: REG_SZ Data: 1
