If you’re having trouble when you open up device manager in a VM and see that some devices are listed as “unknown device.” From Troubleshooting Hyper-V topic on TechNet. Cause: Device Manager doesn’t recognize devices that’re optimized for use in vm and run using Hyper-V until integration services’re installed. The unknown devices that’re identified in Device Manager differ depending on guest operating system and may include: VMBus, Microsoft VMBus HID Miniport, Microsoft VMBus Network Adapter, and storvsc miniport. Solution: If guest operating system is supported, integration services’re available for that operating system. After you install integration services, Device Manager’ll recognize devices that’re available for that guest operating system.

Full Article: TechNet