BootSkin is a freeware program that can change your boot screen on Windows 2000, Windows XP, and even Longhorn (all builds).

It changes boot screens without patching (or replacing!) the Windows kernel which is what most (if not all) the other boot screen changers do.

Because of that, boot screens are very simple to create and use. There are already hundreds of boot screens already available in .BootSkin format.

The release candidate has dozens of tweaks and fixes to provide a more seamless experience for users.

This has 2 advantages:
1) Boot screens that use BootSkin are typically under 20K compared to other boot screen programs whose files are over 2 MEGABYTES.
2) There is no risk of having your system unable to boot due to a corrupted file or after applying a service pack

You can download boot screens from HERE