Web Server

I have installed the VS 2003.net , IIS 5.1 and wanted to use it creating a ASP project.But every times when I click ASP.net web application, there will have a warning"The specified web server is not running ASP.net version 1.1, you will unable to run asp.net web applications and services."Did you try just re-installing .NET 1.1 after the VS.NET installation?
If you install IIS after installing .Net framework, you will need to run a command to register ASP.Net with IIS.

The command is, found in your .Net framework instllation directory:

c:\windows\microsoft.net\framework\<version>\aspnet_regiis.exe -i