Well, there's this....
http://bcubing.deviantart.com/art/Windows-7-Logon-screen-editor-141615089
Or, I think the XP version of LogonStudio has a built in editor, but don't quote me, XP was sooooooo long ago.
LogonStudio 1.7
CNET editors' review
Reviewed by: CNET Staff on January 23, 2009
Longing for some change in your life? Why not start with that boring old Windows XP logon screen? With the freeware LogonStudio, choosing another screen is a matter of two clicks. Alternately, you can design your own with a built-in editor.
