I have spent about half of today working on enabling "Interactive Logon Message title for users attempting to log on" and "Interactive Logon: Message text for users attempting to log" on using group policy. A little background on the office build and what I have tried...
4 Domain Controllers in a forest using sites and services. All DCs are Windows 2008. The test computer is Windows 7. I created an "IT-Test" container and put my user account in the container. I then created a test GPO and linked it to the test container. The test GPO only changes the Interactive Logon Message Text and Title, but the default domain policy is inherited but has precedence 2. My test policy has Precedence 1 and is enforced.
I am using my account and my computer which I am an admin on. The local security policy->local policies does have a lock on the icon on my machine (not sure if that is relevant).
That is all the info that I can come up with. I have rebooted several times and done gpupdate.
Let me know what I am missing or any information to help figure this out.