As part of the installation, some XML fragments (eg: <authentication>) need to be uncommented in web.config file based on the environment,. This can be done either via PowerShell or C#.Net as this has to be triggered from MSI installation. Never during the runtime of the application.
We can either do string-based detection and replace it. Or use XML parser of .Net. Since the string parser is complex, let us stick with the .Net library to replace it.
Read on for one way to do this.