Problems with K8047 with USB ports

Hello.
I have recently bought a K8047 card. I am trying to use it, but I am experiencing some problems that seem to be related with the USB port to which I connect it. I have in fact found different PCs to which I can connect the card see it without problems, and I have been able to record data. The card is therefore working correctly. On the other hand, there are many USB ports that just lead to the message ‘device unknown’ when I connect the board. And, the red led that should blink 3 times then stay off actually remains permanently on after blinking. The problem is that, for my application, this card must forcefully be connected to one specific PC, and no USB port of this PC manage to communicate well with the card.
Do you have any ideas of what could be going on? All the PC I have used run on Windows 7. Any help would be much appreciated!
Thanks!
Martino

Using an external powered USB HUB may help to solve the problem.
Are the problematic USB ports USB 2.0 or 3.0 version?