Registry Settings Reset after editing.

Hi
I have recently taken over tech support of a site from the previous it company, that has windows 2003 server and 6 terminal services users. Admin is done via terminal services (in console mode if required.) I changed the legal notice logon text in the registry (put my own contact nos for support etc. but the next day it was back how it had been. Most weird! I was wondering if there may be o.s. protection or volume shaddowing or something like that causing it to reset. Help would be appreciated. Andrew