Phillip Corcoran said:
Not showing in Device Manager usually means that particular device has developed a fault to the extent that the host computer can no longer detect it.
You could try re-seating the card, it may just be a bad connection between the card's edge-connectors and the contacts in the PCI slot.
I have already done that, I moved all my cards around just to move that one to a separate slot and the results were no better. I have no idea how to fix this, I doubt the device is faulty after only 2 months of use.