Why ASP.NET webapplications/webservies are not running/working on my system?

Question

I have windows 2000 professional edition installed on my system. When I try to open a new project in ASp .NET web applications or web services, I get the following error: "Visual Studio .NET has detected that the specified webserver is not running ASP.NET version 1.1. You will be unable to run ASP.NET web applications or services." Note that Webserver is running propery on my PC. How to resolve this error?