Write-Output "Shutting down all Virtual Machines..."
If (((Get-CimInstance Win32_OperatingSystem).Caption -match 'Microsoft Windows 10') -or ((Get-CimInstance Win32_OperatingSystem).Caption -match 'Microsoft Windows 8')) {
    If ((Get-WindowsOptionalFeature -FeatureName Microsoft-Hyper-V-All -Online).State -eq 'Enabled') {
        Write-Output "Client Hyper-V is enabled."
        $HVHost = "Yes"
    }
    ElseIf ((Get-WindowsOptionalFeature -FeatureName Microsoft-Hyper-V-All -Online).State -eq 'Disabled') {
        Write-Output "Client Hyper-V is not enabled."
    }
    Else {
        Throw "Unable to determine Client Hyper-V state, aborting."
    }
}
ElseIf ((Get-CimInstance Win32_OperatingSystem).Caption -match 'Microsoft Windows Server') {
    If ((Get-WindowsFeature -Name Hyper-V) -eq $true) {
        Write-Output "Server Hyper-V is enabled."
        $HVHost = "Yes"
    }
    ElseIf ((Get-WindowsFeature -Name Hyper-V) -eq $false) {
        Write-Output "Server Hyper-V is not enabled."
    }
    Else {
        Throw "Unable to determine Server Hyper-V state, aborting."
    }
}
Else {
    Throw "Unable to determine Operating system to check Hyper-V state, aborting."
}

Try {
    If ($HVHost -eq "Yes") {
        Write-Output "Shutting down all Virtual Machines..."
        Do {

            $RunningVMs= Get-VM | Where-Object -Property State -eq "Running"
            Foreach ($RunningVM in $RunningVMs) {
                Write-Host (Get-Date)": Shutdown initiated on $($RunningVM.Name)..."
                Stop-VM $RunningVM -AsJob | Out-Null
            }

            If ($RunningVMs) {
                Write-Host (Get-Date)": Virtual Machine shutdown in progress, re-check in 1 minute..."
                Start-Sleep -Seconds 60
            }
        }
        Until ($null -eq $RunningVMs)
        Write-Host (Get-Date)": All Virtual Machines have been shut down."

        Write-Host (Get-Date)": Shutting down host..."
        #Restart-Computer -Force
    }
}
Catch {
    Throw ""
}