Windows XP user logon "Welcome movie"

Hi I'm a new member and I found this site by searching resources on trying to customise my windows XP user logon.

So far I have not been succesfull.

This is my problem:

For those of you who know the game "Command & Conquer: Tiberian Sun";
the game starts with a movie called "Eva uploading".
That movie ends with a tekst printing across the screen ("Welcome Back Commander")

I have extracted that part of the video and turned it into an AVI video file.

Now I want to use that movie when the user logs in.

So when the user logs in I want to show the movie fullscreen BEFORE everything is loaded (taskbar, desktop etc...);

I have tried some things using VLC media player:
- adding a shortcut to the startup folder
- adding a registry item in various places

Now the closest I've gotten is by putting the item in the
"HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce"
registry.

This played the movie while the screen of windows XP still said "Welcome". So I only got the sound and not the movie. And there is the fact that the RunOnce clears itself every reboot, so that doesn't help.

the only possible way to display a movie right after the "Welcome" appears (or instead of that Welcome text) is to alter it in windows itself, but I have no idea where to start.

Getting this solved would help me a LOT.

Thanks in advance,
Marcus

Just to clarify, I want a fullscreen movie to run (preferrably without a player like VLC) before explorer.exe runs, when the movie finished, then the normal booting should commence.