
When you shutdown a single host running Hyper-V it will pause all guests and shutdown. Since HP Uninterruptible Power Supplies (UPSs) are rebranded APC units, you can use the HP or APC software to remotely shutdown the virtual host.

When it's a physical box you can connect to and manage network, USB- and serial connected UPS's (as long as the box offers the right physical connectors and right amount of them)

When the server running System Center Virtual Machine Manager (SCVMM) is running virtually you can connect to, and manage network connected UPSs. Uninterruptible Power Supplies (UPSs) can be configured using network connections, USB connections and some solder models through serial connections.
