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.