If you would like to display a legal message or any other message in a pop-up
window when windows starts read below:
Start Regedit; if you are unfamiliar with Regedit please see our FAQ.
Navigate to HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows
NT/CurrentVersion/Winlogon.
Modify the key “legalnoticecaption” with what you want to name the window.
Modify the key “legalnoticetext” with what you want the window to say.
Restart.