This policy setting allows you to manage whether users can display nonsecure items and manage whether users receive a security information message to display pages containing both secure and nonsecure items.If you enable this policy setting and the drop-down box is set to Enable the user does not receive a security information message (This page contains both secure and nonsecure items. Do you want to display the nonsecure items?) and nonsecure content can be displayed.If the drop-down box is set to Prompt the user will receive the security information message on the Web pages that contain both secure (https://) and nonsecure (http://) content.If you disable this policy setting users cannot receive the security information message and nonsecure content cannot be displayed.If you do not configure this policy setting the user will receive the security information message on the Web pages that contain both secure (https://) and nonsecure (http://) content.
Windows Components\Internet Explorer\Internet Control Panel\Security Page\Locked-Down Local Machine Zone
User
At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
HKCU\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Lockdown_Zones\0!1609
inetres.admx