Unable to start debugging

[jeff]

Greetings
I am new a this, so here goes.

I have set up a .net, C# solution on my XP pro machine. This
application was created on another machine. WHen I try to debug the
app in VS.net 2003, I get the following error:

"Error while trying to run the project: Unable to start debugging on
the web server. Could not start ASP.NET or ATL server debugging.
Verify that ASP.NET or ATL server is correctly installed on the
server."

I am running IIS 5.1.
..NET framework 1.1
I have set my web app configuration /mappings to :
..* mapps to aspnet_isapi.dll


I have also tried running the aspnet_regiis.exe -i to no avail.

If this error message is correct, how do I actually verify that
ASP.NET is correctly installed. Also, what is ATL?

Thanks
Jeff