At this stage of the Exchange Server 2007 scenario for System Center Capacity Planner 2007, you modify hardware for Exchange Server from one configuration to another. You can use the same hardware already in use by another server by choosing a configuration that resembles SiteName\ServerName or select a new pre-defined hardware configuration.To change Exchange Server hardware
In the Model Editor, open the site that contains the simulated server you want to modify the hardware for.
Click the server to modify hardware for, and then click Edit server hardware configuration.
In the Apply New Configuration list, select the hardware configuration to apply to the simulated server, and then click OK.