Why on earth would you want to do such a thing? If you prefer to use the Windows 2000 style Windows Classic Theme and the Windows 2000 style classic logon screen on Windows XP, you'll notice that there is a change in appearance between reaching the logon screen, and then reaching the desktop after logging in. What I'm about to cover is the method that I've discovered of changing the theme on the Windows XP classic style logon screen to use the Windows 2000 style Windows Classic Theme.

People on forums and what not seemingly didn't realise that there was a difference between the Classic Theme, and the Luna theme without the actual visual style applied (what you get when you disable the Themes service). Unfortunately it seemed to be one of those things that confused a lot of people. I searched high and low on the interweb, trying to find someone else that had done it before.