I was developing a windows phone 8 application using VS 2012, and after i did some changes in the network adapter by disabling the hyper-v virtualization protocol "vEthernet" and all its components, the emulator stops working!.
The reason i did this because i wasn't able to give a static IP to my machine so i can access it from my second machine, installing TCP/IP 4 to set the static IP and unchecked Hyper-V protocol screw my virtual Ethernet adapter and emulator components that are using it.
I was looking and searching what caused this problem, the only thing i was sure about it it is something related to the network adapter settings! since the network adapter doesn't have the required settings for the Hyper-V neither The emulator nor the Hyper-V switch manager is working and throwing errors.
The emulator was throwing an error: Generic Failure in VS 2012.
The Hyper-V Switch manager is throwing this error message: An error occurred while trying to retrieve a list of virtual switches.
To cleanup your machine and get back developing on the emulator, do the following:
1) Open Hyper-V Manager, you will find a VM created for your emulator, Delete this VM.
2) From Control Panel, Open Add or Remove windows Features -> Un check Hyper-V. This will un install all Hyper-V configuration. Reboot your machine.
3) From Control Panel, Add back Hyper-V to your windows, this will install Hyper-V manager and install all required vEthernet and other components that are required to run the emulator.
4) Open Hyper-V Manager, Click on "Add Virtual Switch Manager" and then add a virtual switch of type Internal.
Notice: you won't get the error message we had earlier!
5) Open your visual studio, and run your WP8 application, this will configure the emulator VM and all its components.
Notice: The first will take a longer time to run, since the windows will install all required drivers and create the VM used by the emulator and setup the network adapters between the PC and the VM.
6) If you check the Hyper-V manager after the first run for your application, VS 2012 has created a new VM and used the new Virtual Switch we created earlier.
Hope this helps!
Drop me a line if you have this problem and have other solutions or workarounds to it.