Help with Ross Tech Vag Com

I am trying to get this Ross Tech vag com thing to work with my laptop as a
code scanner. I am using it with a 2000 New Beetle. It says I have to test
it before I can use it, and when I try to test it, all I get is an error
message "interface not found". Or, it locks up with the "hourglass" forever.
Can someone tell me what I need to do to get things up & running? Thanks
very much for any assistance.


.