Working in what sense of the word? If you can install it physically, connect it, install drivers and pass traffic on it then it's usually OK. Assuming that you can't do those things then it's a fair bet that there's something wrong.
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CompTIA A+, Network+, Server+, Security+
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator