Sorry if this has been posted before...I think this is the easiest way to create a custom boot screen.
1. - Create a boot screen 640 x 480
Here is an example of one I created. (made for widescreen)
2. Down this free trial program called "Tuneup Utilities" from here..
Download Here
(You can remove program when you are done... screen will stay)
3. Open Tuneup Utilities - Click on "TuneUp Styler 2"
4. Click on "Change the windows XP boot screen, and create or download new boot screens"
5. Click on "New Screen"
6. Click on "Search Local Drives" and browse to the image you created.
After adding the photo click on "Save Boot Screen"
7. You will need to give it a name... Click OK
8. Highlight the screen you want to apply and click on "Install Boot Screen"
YOU ARE DONE....
After you reboot you will notice you now have two boot options. You can remove that by editing the boot.ini file on the root C drive. Just edit it in notepad and remove the line with "(TuneUp Backup)" in it. Here is a screen shot.
Hope this helps someone.