Windows 7/8/10 allows you to add a message that appears on the logon screen when users log in. Use the Local Security Policy Editor to customize the message to users who log on to your computer.
The message is for informational purposes only and does not provide any real security. Depending on what you write, it might scare someone off, but the message is deleted as soon as they click OK. In addition, you can only edit security policy settings in Pro and later versions of Windows. It won’t work in Home and Starter versions.
Edit the Windows logon message
Type the following into the Search programs and files box on the Start menu and press Enter or click the link.
Expand the Local Policies node in the tree in the left pane and select the Security Settings node.
Double-click the Interactive Login: Message Text for Users Trying to Login option in the right pane.
On the Local Policy Setting tab, enter your message in the text box and click OK.
We’ve seen instructions on the internet that say that all you need to do to display a message on the login screen is to enter the text for the setting mentioned above. However, we found that the message is only displayed when we have applied the title to the message. To do this, double-click the Logon Interactive: header of the message for users trying to log on.
On the Local Policy Setting tab, enter a title for the message in the text box and click OK.
To close the Local Security Policy Editor, choose Exit from the File menu.
Your title and message are now displayed on the screen before showing available users. Click “OK” to select a user and log in.
To disable a message, simply go back to the Local Security Policy Editor and delete the message and header. Enjoy!