Product:
Cognos Controller 10.3
Microsoft Windows 2008 R2 server

Symptom:
After installation of Cognos Controller you get an error message when you start Cognos Controller Configuration

Error message in Controller:
Web Service, ControllerProxyServer, could not be found. Section is disabled.
The type initializer for ‘Cognos.Controller.Configuration.CRN’ threw an exception.

Cause:
The IIS installation is damage.

Check by start the IIS manager and expand the Application pool or the site list. You will get error like below:
There was an error while performing this operation
Details:
Filename:
\\?\c:\windows\microsoft.net\framework64\v2.0.50727\CONFIG\web.config
Line number: 13
Error: The configuration section “system.web” cannot be read because it is missing a section declaration.
or
Configuration system failed to initialize.

Possible Solution:
Uninstall IIS from windows and reinstall it from add/remove roles.