If you want to stop Hyper-V virtual machine in case of bandwidth over usage you can use the following VBS script and Hyper-V Bandwidth Meter settings.
You can download script source code below. It stops a virtual machine and also sends email notification to server administrator.
Be sure you have CDO installed on your server and working SMTP localhost server.
Download this script, unzip it and change eml_from
and eml_to
strings in stop.vbs file.