HOW TO STOP YOUR DEVICE FROM KILLING YOUR WINDOWS WIFI NETWORK CONNECTION
In the first place, your computer should be directly connected to your router, preferably via an Ethernet cable.
If you cannot directly connect and have to use WiFi, here is how to make sure that plugging in your device does not instantly kill you WiFi connectivity.
Right click the network adaptor in your task bar and select "Open network and sharing centre"
Click "Change adaptor settings" on the left side of the Network and Sharing Centre
Right click your wireless adaptor and go to "Properties"
In the networking tab, click "Configure"
Go to the Advanced tab and find "Disable upon wired connect" - make sure it is set to "disabled"
For the technically minded:-
Due to the USB/TCP bridge driver, the your device appears to the system as another Network Interface Card, it's the same (to the OS) as if you plugged the PC into a hardwired network.