-s <path> Set the ASP.NET version of the application pool for the specified
application path to ASP.NET version 2.0. If the application pool of the
specified application is the "ASP.NET 1.1", the application pool of the
application is set to "DefaultAppPool". Requires that the "IIS 6 Management
Compatibility" features are enabled.
E.g. aspnet_regiis.exe -s W3SVC/1/ROOT/SampleApp1