Prohibit non-administrators from applying vendor signed updates

This policy setting controls the ability of non-administrators to install updates that have been digitally signed by the application vendor. Non-administrator updates provide a mechanism for the author of an application to create digitally signed updates that can be applied by non-privileged users. If you enable this policy setting only administrators or users with administrative privileges can apply updates to Windows Installer based applications. If you disable or do not configure this policy setting users without administrative privileges can install non-administrator updates.

Allow user control over installs

This policy setting permits users to change installation options that typically are available only to system administrators. If you enable this policy setting some of the security features of Windows Installer are bypassed. It permits installations to complete that otherwise would be halted due to a security violation. If you disable or do not configure this policy setting the security features of Windows Installer prevent users from changing installation options typically reserved for system administrators such as specifying the directory to which files are installed. If Windows Installer detects that an installation package has permitted the user to change a protected option it stops the installation and displays a message. These security features operate only when the installation program is running in a privileged security context in which it has access to directories denied to the user. This policy setting is designed for less restrictive environments. It can be used to circumvent errors in an installation program that prevents software from being installed.

Prohibit rollback

This policy setting prohibits Windows Installer from generating and saving the files it needs to reverse an interrupted or unsuccessful installation. If you enable this policy setting Windows Installer is prevented from recording the original state of the system and sequence of changes it makes during installation. It also prevents Windows Installer from retaining files it intends to delete later. As a result Windows Installer cannot restore the computer to its original state if the installation does not complete. This policy setting is designed to reduce the amount of temporary disk space required to install programs. Also it prevents malicious users from interrupting an installation to gather data about the internal state of the computer or to search secure system files. However because an incomplete installation can render the system or a program inoperable do not use this policy setting unless it is essential. This policy setting appears in the Computer Configuration and User Configuration folders. If the policy setting is enabled in either folder it is considered be enabled even if it is explicitly disabled in the other folder.

Prohibit rollback

This policy setting prohibits Windows Installer from generating and saving the files it needs to reverse an interrupted or unsuccessful installation. If you enable this policy setting Windows Installer is prevented from recording the original state of the system and sequence of changes it makes during installation. It also prevents Windows Installer from retaining files it intends to delete later. As a result Windows Installer cannot restore the computer to its original state if the installation does not complete. This policy setting is designed to reduce the amount of temporary disk space required to install programs. Also it prevents malicious users from interrupting an installation to gather data about the internal state of the computer or to search secure system files. However because an incomplete installation can render the system or a program inoperable do not use this policy setting unless it is essential. This policy setting appears in the Computer Configuration and User Configuration folders. If the policy setting is enabled in either folder it is considered be enabled even if it is explicitly disabled in the other folder.

Prevent users from using Windows Installer to install updates and upgrades

This policy setting prevents users from using Windows Installer to install patches. If you enable this policy setting users are prevented from using Windows Installer to install patches. Patches are updates or upgrades that replace only those program files that have changed. Because patches can be easy vehicles for malicious programs some installations prohibit their use. Note: This policy setting applies only to installations that run in the user’s security context. If you disable or do not configure this policy setting by default users who are not system administrators cannot apply patches to installations that run with elevated system privileges such as those offered on the desktop or in Add or Remove Programs. Also see the “Enable user to patch elevated products” policy setting.

Turn off Windows Installer

This policy setting restricts the use of Windows Installer. If you enable this policy setting you can prevent users from installing software on their systems or permit users to install only those programs offered by a system administrator. You can use the options in the Disable Windows Installer box to establish an installation setting. — The “Never” option indicates Windows Installer is fully enabled. Users can install and upgrade software. This is the default behavior for Windows Installer on Windows 2000 Professional Windows XP Professional and Windows Vista when the policy is not configured. — The “For non-managed applications only” option permits users to install only those programs that a system administrator assigns (offers on the desktop) or publishes (adds them to Add or Remove Programs). This is the default behavior of Windows Installer on Windows Server 2003 family when the policy is not configured. — The “Always” option indicates that Windows Installer is disabled. This policy setting affects Windows Installer only. It does not prevent users from using other methods to install and upgrade programs.

Prevent removable media source for any installation

This policy setting prevents users from installing any programs from removable media. If you enable this policy setting if a user tries to install a program from removable media such as CD-ROMs floppy disks and DVDs a message appears stating that the feature cannot be found. This policy setting applies even when the installation is running in the user’s security context. If you disable or do not configure this policy setting users can install from removable media when the installation is running in their own security context but only system administrators can use removable media when an installation is running with elevated system privileges such as installations offered on the desktop or in Add or Remove Programs. Also see the “Enable user to use media source while elevated” and “Hide the ‘Add a program from CD-ROM or floppy disk’ option” policy settings.

Turn off logging via package settings

This policy setting controls Windows Installer’s processing of the MsiLogging property. The MsiLogging property in an installation package can be used to enable automatic logging of all install operations for the package. If you enable this policy setting you can use the options in the Disable logging via package settings box to control automatic logging via package settings behavior. — The “Logging via package settings on” option instructs Windows Installer to automatically generate log files for packages that include the MsiLogging property. — The “Logging via package settings off” option turns off the automatic logging behavior when specified via the MsiLogging policy. Log files can still be generated using the logging command line switch or the Logging policy. If you disable or do not configure this policy setting Windows Installer will automatically generate log files for those packages that include the MsiLogging property.

Prohibit flyweight patching

This policy setting controls the ability to turn off all patch optimizations. If you enable this policy setting all Patch Optimization options are turned off during the installation. If you disable or do not configure this policy setting it enables faster application of patches by removing execution of unnecessary actions. The flyweight patching mode is primarily designed for patches that just update a few files or registry values. The Installer will analyze the patch for specific changes to determine if optimization is possible. If so the patch will be applied using a minimal set of processing.

Remove browse dialog box for new source

This policy setting prevents users from searching for installation files when they add features or components to an installed program. If you enable this policy setting the Browse button beside the “Use feature from” list in the Windows Installer dialog box is disabled. As a result users must select an installation file source from the “Use features from” list that the system administrator configures. This policy setting applies even when the installation is running in the user’s security context. If you disable or do not configure this policy setting the Browse button is enabled when an installation is running in the user’s security context. But only system administrators can browse when an installation is running with elevated system privileges such as installations offered on the desktop or in Add or Remove Programs. This policy setting affects Windows Installer only. It does not prevent users from selecting other browsers such as File Explorer or Network Locations to search for installation files. Also see the “Enable user to browse for source while elevated” policy setting.