Summary: Sean Kearney explains how to use Windows PowerShell to find running virtual machines.
How can I find a list of virtual machines on my computer that is running Windows Server 2012 with Hyper-V?
Use the Get-VM cmdlet and filter on the State property:
Get-VM | Where { $_.State -eq 'Running' }
Or if you need to check a remote computer:
Get-VM -computername RemoteHyperVServer | Where { $_.State -eq 'Running' }\