Deferred, commit, and rollback custom actions in Basic MSI and InstallScript MSI installations have access to only some of the built-in Windows Installer properties: CustomActionData, ProductCode, and UserSID. If you want a custom action to access any other properties during deferred, commit, or rollback execution, you can pass them as CustomActionData. You can do so by scheduling an immediate set-a-property type of custom action to set a property that matches the name of the custom action. The value of this property is then available in the CustomActionData property within the deferred, commit, or rollback custom action.