You can create a funny message or legal warnings for others just before logon to your computer. This is very useful if you want to give a message to new user about the use of computer. Edit the value of registry keys to create a banner message.
Click Start button then type regedit in Run option then press Enter for next.
Here locate the location to:
HKeyLocalMachine \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Win Logon
Here in right side panel, right click to create a new string value LegalNoticeCaption and give it a value you want to see in the menu bar
Now again right click to create a new string value called LegalNoticeText and change the value you want to see in the dialog box
Now close the registry editor and restart your computer after any changes to go into effect.