IIS 6 and ASP.NET 4 Question

HI everyone

I need some help in clarifying the following issue:

Is the .svc application extension part of IIS6 and ASP.NET4 ? It doesnt show in the application extensions as a default extension.

 I've installed a new  Windows 2003 server and ASP.NET4.0., however when I try to browse a URL that ends with .svc, I get a 404 file or folder not found?

I can browse the site if I manually add the .svc application extension however.

I've tried a few of the suggestions on Technet and other sites, eg: servicemodelreg-exe -i , but so far nothing has worked, besides manually adding the application extension.

Thanks in advance.