There are lots of times where you may wish to perform actions prior to logon, during an unattended build process especially. The NT Resource Kit contains a great tool called AutoExNt that can help you do just that.

The AutoExNt service allows you to run a batch file, Autoexnt.bat, when you boot NT without having to log on to that computer. AutoExNT.exe is a service which will run the autoexnt.bat file. AutoExNt is an NT Resource Kit utility. You use instexnt install command to install AutoExNt. To allow AutoExNt to function, set the service to start automatically in Control Panel / Services. Contact rkinput@microsoft.comfor questions or feedback concerning this utility.

Microsoft KB Article Q243486 Explains Its Use