Web sites and Web applications depend on the availability of Internet Information Services (IIS) application pools. IIS application pools in turn depend on the Windows Process Activation Service (WAS). If WAS is not running or errors occur during the startup or shutdown of an application pool, Web sites and Web applications may not be available.
Change the application pool name
To change the application pool name:
Click Start, click Control Panel, and then click Administrative Tools.
Right-click Internet Information Services (IIS) Manager and select Run as administrator.
In the Connections pane, expand the server node and click Application Pools.
On the Application Pools page, select the application pool you want to rename.
In the Actions pane, under Edit Application Pool, click Rename, type the new name in the rename text box, and then press ENTER or click outside the rename text box.