I received an error message when i create a new web application, the error message as follows : "Visual Studio .NET has detected that the specified web server is not running ASP.NET version 1.1. You will be unable to run ASP.NET Web application oe services"

This occur becoz ur webserver is not running , first go to control panel->administrative tools->IIS.
in this see whether the IIS is running or not.
If it is not running then again install iis by taking corresponding operating system cd
:)