Hi Ninetto,
When this problem occurs, please check to see if you still see the device listed in Windows Device Manager under Sound, Video and Game Controllers. If not, it would suggest that the system itself is not detecting the hardware. If this is the case I think it's likely there's a conflict somewhere in the system. In the past I have seen similar problems where the DeckLink card in a slot that shares a PCIe bus with another device, such as the graphics card. I would suggest trying the DeckLink card in different PCIe slots if possible. But if this does not help, please do contact your regional support team, either using the numbers on the following page
http://www.blackmagic-design.com/company/
Or using the support request form from the product's section in the support pages here
http://www.blackmagic-design.com/support/
Chris Pearse
Blackmagic Design
