PowerShell: Get All Hyper-V Servers in the Domain or Forest

function getHyperVHostsInForest{
    function includeRSAT{
        $ErrorActionPreference='stop'
        [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
        #$rsatWindows7x32='https://download.microsoft.com/download/4/F/7/4F71806A-1C56-4EF2-9B4F-9870C4CFD2EE/Windows6.1-KB958830-x86-RefreshPkg.msu'
        $rsatWindows7x64='https://download.microsoft.com/download/4/F/7/4F71806A-1C56-4EF2-9B4F-9870C4CFD2EE/Windows6.1-KB958830-x64-RefreshPkg.msu'
        $rsatWindows81='https://download.microsoft.com/download/1/8/E/18EA4843-C596-4542-9236-DE46F780806E/Windows8.1-KB2693643-x64.msu'
        $rsat1709 = "https://download.microsoft.com/download/1/D/8/1D8B5022-5477-4B9A-8104-6A71FF9D98AB/WindowsTH-RSAT_WS_1709-x64.msu"
        $rsat1803 = "https://download.microsoft.com/download/1/D/8/1D8B5022-5477-4B9A-8104-6A71FF9D98AB/WindowsTH-RSAT_WS_1803-x64.msu"
        $rsatWs2016 = "https://download.microsoft.com/download/1/D/8/1D8B5022-5477-4B9A-8104-6A71FF9D98AB/WindowsTH-RSAT_WS2016-x64.msu"
  
        # This command does not work on Windows 2012R2
        #$releaseId=(Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion" -Name ReleaseId).ReleaseId
        #Get-ItemProperty : Property ReleaseId does not exist at path HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
        #NT\CurrentVersion.
        #At line:1 char:2
        #+ (Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion" -Na ...
        #+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        #    + CategoryInfo          : InvalidArgument: (ReleaseId:String) [Get-ItemProperty], PSArgumentException
        #    + FullyQualifiedErrorId : System.Management.Automation.PSArgumentException,Microsoft.PowerShell.Commands.GetItemPropertyCommand
  
        $releaseId=(Get-Item "HKLM:SOFTWARE\Microsoft\Windows NT\CurrentVersion").GetValue('ReleaseID')
        $osVersion=[System.Environment]::OSVersion.Version
        [double]$osVersionMajorMinor="$($osVersion.Major).$($osVersion.Minor)"  
        $osName=(Get-WmiObject Win32_OperatingSystem).Name
        #$osType=switch ((Get-CimInstance -ClassName Win32_OperatingSystem).ProductType){
        #    1 {'client'}
        #    2 {'domaincontroller'}
        #    3 {'memberserver'}
        #    }
  
        $windowsVersion=(Get-CimInstance Win32_OperatingSystem).Version
  
        switch ($releaseId){
            1607{write-host 'Windows Server 2016 Release 1607 detected';$link=$rsatWs2016;break}
            1709{write-host 'Windows Server 2016 Release 1709 detected';$link=$rsat1709;break}
            1803{write-host 'Windows Server 2016 Release 1803 detected';$link=$rsat1803}
        }
      
        switch ($osVersionMajorMinor){
            {$_ -eq 6.0}{write-host 'Windows Server 2008 or Windows Vista detected';$link=$rsat1709;break}
            {$_ -eq 6.1}{write-host 'Windows Server 2008 R2 or Windows 7 detected';$link=$rsatWindows7x64;break}
            {$_ -eq 6.2}{write-host 'Windows Server 2012 or Windows 8.1 detected';$link=$rsatWindows81;break}
            {$_ -eq 6.3}{write-host 'Windows Server 2012 R2 detected';$link=$rsatWindows81}
        }
 
        if (!(Get-Module -ListAvailable -Name ActiveDirectory -EA SilentlyContinue)){
            Write-host "Prerequisite checks: module ActiveDirectory NOT currently available on this system. Please wait while the program adds that plugin..."
            try{
                # If OS is Windows Server, then install RSAT using a different method
                if ($osName -match "^Microsoft Windows Server") {
                    # This sequence has confirmed to be valid on Windows Server 2008 R2 and above
                    Write-Verbose "Importing Windows Feature: RSAT-AD-PowerShell"
                    Import-Module ServerManager
                    Add-WindowsFeature RSAT-AD-PowerShell
                    }
                else{
                    Write-Verbose "This sequence targets Windows Client versions"
                    $destinationFile= ($ENV:USERPROFILE) + "\Downloads\" + (split-path $link -leaf)
                    Write-Host "Downloading RSAT from $link..."
                    Start-BitsTransfer -Source $link -Destination $destinationFile
                    $fileCheck=Get-AuthenticodeSignature $destinationFile
                    if($fileCheck.status -ne "valid") {write-host "$destinationFile is not valid. Please try again...";break}
                    $wusaCommand = $destinationFile + " /quiet"
                    Write-host "Installing RSAT - please wait..."
                    Start-Process -FilePath "C:\Windows\System32\wusa.exe" -ArgumentList $wusaCommand -Wait
                    }
                return $true
                }
            catch{
                write-warning "$($error[0].Exception)"
                return $false
                }
        }else{
            Write-host "Prerequisite checks: module ActiveDirectory IS currently available on this system." -ForegroundColor Green
            return $true
            }
    }

    function listAllHyperVNodes($verbose=$true){
        try{
            $timer=[System.Diagnostics.Stopwatch]::StartNew()
            $domains=(Get-ADForest).Name|%{(Get-ADForest -Identity $_).Name}
            foreach ($domain in $domains){
                #[string]$dc=(get-addomaincontroller -DomainName "$domain" -Discover -NextClosestSite).HostName
                write-host "Collecting all Hyper-V Clusters in $domain. This may take a while, depending on cluster sizes."
                $allClusters=(get-cluster -domain $domain).Name
                if($verbose){
                    $elapsed=[math]::round($timer.Elapsed.TotalMinutes,2)
                    write-host "Minutes elapsed $elapsed`: cluster names collected"
                    }
                $nodes=$allClusters|%{try{Get-ClusterGroup -Cluster $_ -ea SilentlyContinue}catch{}}
                if($verbose){
                    $elapsed=[math]::round($timer.Elapsed.TotalMinutes,2)
                    write-host "Minutes elapsed $elapsed`: Hyper V node names collected"
                }
                $hyperVs=($nodes|Group-Object -Property OwnerNode).Name
                if($verbose){
                    $elapsed=[math]::round($timer.Elapsed.TotalMinutes,2)
                    write-host "Minutes elapsed $elapsed`: Hyper V node names collected - Done!"
                    }
                }
            return $hyperVs
        }catch{
            Write-Error $_
            return $false
            }
    }
 
function sortArrayStringAsNumbers([string[]]$names){
    $hashTable=@{}
    foreach ($name in $names){
        $value=.{
            [int]([regex]::match($name,'^(.*?)(\d+)(\D*)$').groups[2].value)
            }
        $hashTable.Add($name,$value)
        }
    $sorted=foreach($item in $hashTable.GetEnumerator() | Sort Value){$item.Name}
    return $sorted
}

    try{
        $null=includeRSAT;
        $hyperVHosts=listAllHyperVNodes
        $hyperVHostNames=sortArrayStringAsNumbers $hyperVHosts
        return $hyperVHostNames
    }catch{
        Write-Error $_
        return $false
        }
    }

# Short Version
function listAllHyperVNodes($verbose=$true){
    try{
        $timer=[System.Diagnostics.Stopwatch]::StartNew()
        $domains=(Get-ADForest).Name|%{(Get-ADForest -Identity $_).Name}
        foreach ($domain in $domains){
            #[string]$dc=(get-addomaincontroller -DomainName "$domain" -Discover -NextClosestSite).HostName
            write-host "Collecting all Hyper-V Clusters in $domain. This may take a while, depending on cluster sizes."
            $allClusters=(get-cluster -domain $domain).Name
            if($verbose){
                $elapsed=[math]::round($timer.Elapsed.TotalMinutes,2)
                write-host "Minutes elapsed $elapsed`: cluster names collected"
                }
            $nodes=$allClusters|%{try{Get-ClusterGroup -Cluster $_ -ea SilentlyContinue}catch{}}
            if($verbose){
                $elapsed=[math]::round($timer.Elapsed.TotalMinutes,2)
                write-host "Minutes elapsed $elapsed`: Hyper V node names collected"
            }
            $hyperVs=($nodes|Group-Object -Property OwnerNode).Name
            if($verbose){
                $elapsed=[math]::round($timer.Elapsed.TotalMinutes,2)
                write-host "Minutes elapsed $elapsed`: Hyper V node names collected - Done!"
                }
            }
        return $hyperVs
    }catch{
        Write-Error $_
        return $false
        }
}