In Hyper-V 2012r2 a new integration service has been added called Guest services.
By default the new service is unchecked. but what can we do with it?
Guest Services provides the ability to copy files into running VM’s without accessing any virtual network connections those VM’s may have. This means that we can copy and update files inside VM’s even in situations where those VM’s are disconnected from virtual networks, are connected to Private virtual network switches, or are located on networks that are isolated from the underlying host.
Instead of using virtual network switch connections and shared folders to transfer files into each VM, Guest Services instead copies the files across the Hyper-V Virtual Machine Bus (VMBus) to which each VM is connected for high-speed host device driver access. By leveraging the VMBus for file copies, Guest Services makes it really easy to keep files inside VM’s up-to-date regardless of the state of VM network connectivity.
After being enabled you can use the copy-vm powershell command to copy file directly in to running VM’s.