I had Hyper-V installed and working on my Windows 8.1 Pro system without any problems until now.

I was accessing the drivers via my network and it suddenly locked up on me and I couldn't connect to it.

Upon further investigation I cannot access the Virtual Switch Manager and the Network Adapter shows up with 

"Windows cannot initialize the device driver for this hardware. (Code 37) {Operation Failed}

The requested operation was unsuccessful."

I have tried to uninstall and reinstall it manually both via the protocols in the network adapters and via the Device Manager but it still shows up with the same error.

I have removed and reinstalled Hyper-V on Windows and I have rebooted continually to test it.

I'm at a loss and don't know what to to to remove this fully and reinstall fresh.  Any ideas or suggestions would be welcome.

Hi Bradley,

Will the network adaptor on the host machine work fine?

Considering the virtual adaptor is based on the physical network adaptor, have you tried to reinstall the network adaptor on the host machine?

We can take the following steps to reinstall the driver.
1.In the device's Properties dialog box, click the Driver tab, and then click Uninstall. Follow the instructions.
2.Restart your computer.
3.Open Device Manager, click Action, and then click Scan for hardware changes. Follow the instructions.
Note You may be prompted to provide the path of the driver. Windows may have the driver built-in, or may still have the driver files installed from the last time that you set up the device. However, sometimes, it will open the New Hardware Wizard which may ask for the driver. If you are asked for the driver and you do not have it, you can try to download the latest driver from the hardware manufacturer's website.

Best r

Thanks for the advice.

I have tried to uninstall the physical adapter but I get a bluescreen when it attempts the uninstall.  I have tried it in safe mode too, with the device disabled, but still get a bluescreen.

I get a bluescreen if I try to remove my Hyper-V Adapter too.

I have a feeling that something is fundamentally wrong with networking or the adapters but not sure if there's a repair option anywhere.

I did try this but it also hasn't fixed it: https://support.microsoft.com/en-us/kb/299357

Hi Bradley,

We could try the following tools to have a diagnostic.
Control Panel\All Control Panel Items\Troubleshooting\All Categories\Hardware and Devices, Network Adaptor

Please also run "dism /online /cleanup-image /restorehealth" to check the health of the system files.
To analyze this issue deeply, please upload the .dmp files (C:\Windows\Minidump)to the OneDrive and paste the link here.

Best regards

Thank you for the advice.

I spent quite a bit of time trying to remove unnecessary devices and drivers.  After multiple restarts I finally was able to remove Hyper-V and add it again and my Virtual Switch Manager works once more.

Now I'm able to create a switch and access my VM using RDP.  However, something is wrong with the Virtual Machine Connection tool.  When I right click on a VM that's running and select Connect it is unable to establish a connection.  I get:

"Cannot connect to the virtual machine.  Try to connect again.  If the problem persists, contact your system administrator.

Would you like to try connecting again?"

I get around it using RDP but this concerns me that something isn't quite right with the installation.

Thanks so far for your assistance.

Thank you for the advice.

I spent quite a bit of time trying to remove unnecessary devices and drivers.  After multiple restarts I finally was able to remove Hyper-V and add it again and my Virtual Switch Manager works once more.

Now I'm able to create a switch and access my VM using RDP.  However, something is wrong with the Virtual Machine Connection tool.  When I right click on a VM that's running and select Connect it is unable to establish a connection.  I get:

"Cannot connect to the virtual machine.  Try to connect again.  If the problem persists, contact your system administrator.

Would you like to try connecting again?"

I get around it using RDP but this concerns me that something isn't quite right with the installation.

Thanks so far for your assistance.

• Proposed as answer by MeipoXuMicrosoft contingent staff, Moderator Tuesday, June 02, 2015 2:00 AM

Do you have any thoughts on why I cannot connect to a VM directly from the Hyper-V Manager?

Hi Bradley,

Please check the status of " vmms.exe (virtual machine management service)" (services.msc).
There may be a conflict caused by a third party service. We can perform a clean boot to have a troubleshoot. If the issue disappear in clean boot environment, we can enable the third party service one by one to find out the culprit.

Here is a similar symptom for refernece:
Client Hyper-V "Cannot Connect to Virtual Machine"
https://social.technet.microsoft.com/Forums/office/en-US/5c4166d6-db27-4650-9f8f-5f3cc7e57d7f/client-hyperv-cannot-connect-to-virtual-machine?forum=w8itprovirt

How to perform a clean boot in Windows
https://support.microsoft.com/en-us/kb/929135

Best regards