Computer Configuration\Administrative Templates\Windows Components\Windows Installer
Disables or restricts the use of Windows Installer.
This policy can prevent users from installing software on their systems, or permit users to install only those programs offered by a system administrator.
If you enable this policy, you can use the options in the Disable Windows Installer box to establish an installation policy.
Note
This policy affects Windows Installer only. It does not prevent users from using other methods to install and upgrade programs.