>I installed ASP.NET 2.0 application on web server running Server 2003.
>
>1.In the IIS I created a Web Site pointing to the directory c:\inetpub\wwwroot\myapp where application pages are installed.
>2.Under the new Web site I added New Virtual directory pointing to the same directory.
>3. Checked all properties of the web site and virtual directory, all seem to be ok.
>
>I can run an .HTML page from this site but if I try to run any .ASPX pages, IE gives us either 403.1 or 404 error. As if IIS does not recognize ASP.NET as a valid page. Or maybe a security issue.
>
>Any suggestions what to do?

Your site is probably not enabled for .NET. Check in the global properties of the IIS server and make sure that the ASP.NET related components are enabled.