Yellow bang in device manager if SR-IOV NIC is moved to noncapable slot on Windows Server 2012

Applies to: Windows Server 2012 DatacenterWindows Server 2012 Standard


On some SR-IOV capable platforms, some slots are SR-IOV capable, while others are not. If SR-IOV is enabled on a network adapter while inserted into one of the working slots and a virtual switch is created with SR-IOV enabled, the connection will function correctly. However, if the network adapter is then removed from the working slot and placed into a non-SR-IOV capable slot, the driver will fail to load and the device status within Device Manager will indicate a yellow bang error Code 10.


When the network adapter is moved to a different slot, Server 2012 recognizes the same NIC device serial number and attempts to initialize the SR-IOV feature when the driver starts. However, this fails since the slot does not support SR-IOV. When this happens, the driver cannot automatically detect that SR-IOV is not functional and tries to enable SR-IOV. This causes the driver load to fail and an error status is indicated in Device Manager. 


There are three workarounds that are available to correct the device error reported by Device Manager:
- Go to the Advanced settings for the NIC driver and disable SR-IOV. This can be found under the Network and Sharing Center by choosing "Change adapter settings". Right-click on the connection and choose Properties, then choose Configure, and then choose the Advanced settings folder.
- Within Virtual Switch Manager, remove the Hyper-V virtual switch that is bound to this device and recreate it.
- Move the network adapter back into an SR-IOV capable slot