Add this to a script and run it on each system. You can remove the Username part and the AutoAdminLogon part if you don't want the main users name trying to logon (leave these if you have an open lab environment) save this as a .reg file.
Something like this can be run once or more often as needed. You could save it as a autologon.reg or autodomain.reg file.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
"AutoAdminLogon"="1"
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
"DefaultDomainName"="Your-DOMAIN"
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
"DefaultUserName"="UserName"
Edited due to a lack of proper caffine levels. ;-)