Create Your Own Logon Message.

Fallow the steps:

1. Click start
2. click run
3. type regedit, then click ok!
4. In The registry editor, drill down to the following key:
   hklm\software\Microsoft\Windows NT\Current version\Winlogon.
5. Right click LegalNoticeCaption,
6. click modify,
7. Type:Your Message,and then click ok!
8. Right click legalNoticeText,
9. click modify, and then Close your message!
10. Restart Your Computer.
11. The message will appear every time you logon!