Allows users to install programs from removable media, such as floppy disks and CD-ROMs, during privileged installations.
This setting permits all users to install programs from removable media, even when the installation program is running with elevated system privileges. By default, users can install programs from removable media only when the installation runs in the user's security context. During privileged installations, such as those offered on the desktop or displayed in Add or Remove Programs, only system administrators can install from removable media.
This setting does not affect installations that run in the user's security context. By default, users can install from removable media when the installation runs in their own security context.
Also, see the "Prevent removable media source for any install" setting in User Configuration\Administrative Templates\Windows Components\Windows Installer.