Warning, when you run same installer twice (WIX)

How I can perform showing message, that'll tell to user >>This version has already installed<< or some another warning message, when user try to run 开发者_C百科the same installer twice?

Best practice for Windows Installer in the case of running the exact same installer twice is to present the user with a maintenance experience. Here the user can Add/Remove features, perform a Repair or perform an Uninstall.