I am using Wix3 to install WCF service to IIS.
How can I use my custom action (c#) function after installation completed? i.e. I need to open installed web.config file a
There is a sequence of Actions in Windows Installer. The WiX tutorial has a good section on events (and is a great resource anyway).
A typical example of getting something to run after InstallFinalize is to get the installed app to start.
NOT Installed