VirtualDJ – the controller has not been detected

Hey everyone,
I have some issues with VirtualDJ and I don’t know what is wrong.
Recently I got Numax Mixtrack pro, everything with this hardware is okay. My friend told me that VirtualDJ is great software for it and I install it on my computer (Windows Vista).
Everything is fine with the hardware, but when I want to start VirtualDJ there is error message. Any suggestion, answer will be appreciated.
Thank you

VirtualDJ
The controller has not been detected.
Please plug the controller and start VirtualDJ again.
OK
