How to install multiple instances of netvmini using Dpinst.exe?

I have tried installing netvmini sample in the windows ddk…through add hardware from the control panel ,so can install instances of the netvmini driver from the add hardware from the control panel…bUt then i tried installing the netvmini dirver using Dpinst.exe using the DIFx tools of windows …so it installs one instance of the driver…but when i run the setup (Dpinst.exe)again to install the 2nd instance …it doesnt install the second instance …it just updates the first initially loaded instance…

so how can i install multiple instances of netvmini driver using a installer(Dpinst.exe)???