Hello;
The best way to deal with this sort of problem is by uninstalling the NI-DAQ driver completely, and reinstall the board.
If that still doesn't work, try to change the slot where your board is plugged in, and if even that doesn't work, try the board in a different machine.
If the board doesn't work at the other machine, most likely the board has a hardware failure and must be sent back to NI to be repaired.
Hope this helps.
Filipe