samiup

Hi all, i was wondering if anybody knew how to change the windows server 2008 logon screen's wallpaper? i tried several utility softwares like "Logon studio" etc... but none of them seems to do it (at least not on 2008 server). i also tried some manual hacks like attempting to change the system32\imageres.dll using a resource editor... unfortunatly none of those methods is giving any results... can anyone plz point me in the right direction? Thanks!