Enabling Hyper-V on Windows 10 21H2 cuts internet connection

Question

From a pristine Windows 10 21H2 install on my HP EliteDesk 705 G3, I turn on the Hyper-V feature with all subcomponents. Upon restarting I no longer have an internet connection. Looking at the adapters I see that the physical adapter is marked as unplugged (even though it is clearly plugged). Do you have any pointers for me on what to check to allow Hyper-V to work on my machine?

Note that this is before any virtual machines are created at all. In the Virtual Switch Manager I just see the automatically created default switch.

Turning the feature off again re-enables the network connection, but if I were actually able to use Hyper-V on my computer it'd be better :-)

Answer 1

This is how Hyper-V works. Notice that you now have a virtual Ethernet. In order for Hyper-V to allow network access to VMs it injects a virtual network driver onto the host machine. It is this virtual adapter that your entire machine will now use. So once you install Hyper-V you will always be using the virtual adapter instead of your physical one. You point the virtual switch (which is where the virtual adapter comes from) to the physical adapter. Hence your machine (and any VMs using that virtual switch) now use the virtual adapter(s) that were set up by Hyper-V. The virtual adapter uses your physical adapter (which can no longer be used directly by the host because that would conflict with Hyper-V's usage).

Your machine should be working fine. There is a blip when there is a Hyper-V virtual network change because the virtual driver resets but otherwise you shouldn't see any issues. Note that if you add additional virtual networks in Hyper-V then you'll see additional virtual network adapters as well. For example on my machine I have 3 virtual adapters but only 2 physical adapters.

Answer 2

The network cable is completely fine - once I turn off the Hyper-V features and restart, connection is back. The network troubleshooter couldn't identify an issue.

Answer 3

Hello,
Indeed, there are a lot of adapters showing up in Device Manager:

Disabling and re-enabling the adapters didn't help.

The services you mentioned are running.

Answer 4

Hello cooldadtx,
I appreciate the help. Here is what I see when going to the Network and Sharing center if Hyper-V is activated (nothing)

And here is how it looks when Hyper-V is deactivated

As for the network protocols that are enabled for the physical adapter, here they are:

Answer 5

Hello,
Sorry about the confusion, the WiFi I mentioned was when we tried activating it on a laptop on the same network to validate that it's not something else blocking it. The machine where it disconnects only has the Broadcom Ethernet connection (for 802.11x I asked my colleagues but they claim that they never fully activated it even though clearly the group policy is in place - something I'll dig deeper on)

I will be working remotely next week so I can't risk bricking the connection unfortunately. But I'll continue to investigate and have also ordered some new material so that I can try out alternative scenarios.

I will reply here if I get it working or find out something new.

Best,

Sebastian