Did you list your site as "http://localhost/VDBuild/596p3" or as "http://localhost/VDBuild/596p3/%file%"? Because it should be "http://localhost/VDBuild/596p3/%file%".
Also, see the FAQ "Do I need to configure my server?". This covers IIS, and how you might have to set the mime-type of *.wyu and *.wys files as "application/octet-stream".
Tell me if this helps.