Change a VM to have more than 4 VCPUs in MS Hyper-V

# Set here the name of the VM as it is shown in the Hyper-V Manager and the number of VCPUs we want to allocate to it
$VMname = "foo"
$VCPUs = 12

if ($VCPUs -lt 1)
    {
    Write-Host "Cannot assign $VCPUs cores... Sorry :-("
    break
    }

# Get the Virtual Machine Management Service
$VMMS = Get-WmiObject -Computername localhost -Namespace "root\virtualization" -Class "MSVM_VirtualSystemManagementService"

# Get the object corresponding to the virtual machine you want to modify
$VM = Get-WmiObject -Computername localhost -Namespace "root\virtualization" -Class "MSVM_ComputerSystem" | where {$_.ElementName -like $VMname}

if ($VM -eq $null)
    {
    Write-Host "Virtual machine not found. Please check the name and try again."
    break
    }

# Get the object corresponding to that VM's settings
$VMSettings = $VM.getRelated("MSVM_VirtualSystemSettingData") | select -first 1

$GUID = $VMSettings.SystemName
$FileName = "C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines\" + $GUID + ".xml"

$xml = [xml] (Get-Content $FileName)
Write-Host "Current CPU Count: " $xml.configuration.settings.processors.count."#text"
$xml.configuration.settings.processors.count."#text" = "$VCPUs"
Write-Host "New CPU Count: " $xml.configuration.settings.processors.count."#text"

Write-Host "Please wait... Do not stop execution and ignore possible warnings about VMMS stopping; they are intended."
Stop-Service vmms
$xml.Save($FileName)
Start-Service vmms
Write-Host "Done!"