Configuring Application Settings in IIS 7
Applies To: Windows 7, Windows Server 2008, Windows Server 2008 R2, Windows Vista
Configure application settings when you want to store key/value pairs as part of your configuration in the Web.config file. Application settings provide a quick and easy to access area to store configuration data for your application.
For information about the levels at which you can perform these procedures, and the modules, handlers, and permissions that are required for these procedures, see Application Settings Feature Requirements (IIS 7).