To assign a Web Application to a web directory:
In Windows 2003: Choose Application Pool from the drop-down box and click Submit.
In Windows 2008: Choose Application Pool from the drop-down box, specify application pool parameters if Shared Application pool is chosen, click Submit.
You can edit and delete web applications.
Note: Applications with different versions of ASP.NET enabled cannot run in the same application pool, either dedicated or shared.
In Windows 2003, changing ASP.NET version for an application from a shared pool will automatically move it to another predefined shared pool. Parallels H-Sphere will not allow you to change ASP.NET version to, for instance, 1.1 if the application is run in a dedicated pool which has other applications with ASP.NET 2.0.
In Windows 2008, if ASP.NET is enabled for web application, you can select dedicated application pool with ASP.NET support or select ASP.NET version for shared application pool. If ASP.NET is disabled for web application only dedicated application pools without ASP.NET support are available for selection and the only available option for shared application pool is 32-bit applications support.