Not sure if this works here, but works like a charm every time and not many people know about it but try it:
Boot Download Mode>Hit Up>Connect to PC>Windows should recognize and look for updates for the drivers>Check the status of the driver install Note: If everything is complete, continue
>disconnect>remove battery then put back in>
boot normally> Connect to PC>Voila
Hope this helps!
Rooted AT&T Samsung Galaxy S III running latest Quantum 3 RC5
This phone runs smooth like a red-hot knife through softened butter!
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