Windows 7 Trick : Display message before user logon

Before the user logs in into his account, you can display a message by doing a simple tweak in the Local Security Policy editor. This message can be anything like a security message, or an information message or just a fun message like 'Have A Nice Day' or 'Happy Computing'.Open the Security Policy Editor by typing 'secpol.msc' in the Start Menu. Go through Local Policies and then Security Options. Now perform the following steps.

1.On the Right Hand side of the window locate the Interactive logon: Message title for users attempting to log on policy. Double click on it to edit it.

2.Under the Local Security Settings tab, type a title that you would like the users to see for the message, and   click OK. Next,
3. Locate the Interactive logon: Message text for users attempting to log on  policy. Right-click it and select Properties.
4. On the Local Security Settings tab, type your message and click OK.
5. Exit the Local Policy Editor and Reboot the machine to see the changes.