DDJ-200 Not linking to PC Running Rekordbox

My DDJ-200 isn't linking to my desktop PC running Rekordbox.

It runs with my laptop OK.

When I connect the unit, all the lights flash and then go out 

At this point on the laptop, the midi light flashes and then it seems I need to press the Master button to connect?

On the PC all the lights go out, and the midi light  flashes then goes out.  If I push the Master  button it lights up, but nothing else happens.

Any idea what is wrong?  I have tried a number of different USB ports on the PC?

Can I check anywhere else on it as to wha tthe connection status might be (it makes all the appropriate boingy noises when I plug it in and unplug it)