Set VM Tools to Update Automatically on VM Reboot using powershell

$UpgradePolicy = "upgradeAtPowerCycle"      # Other option: manual

Write-Host "Setting all VM Tool's upgrade policy to $UpgradePolicy"

Write-Host "Get list of VMs to update..."
$vms = Get-VM
Write-Host ("...got " + $vms.count + " VMs")

# Create config spec to apply
$VMcfgSpec = New-Object VMware.Vim.VirtualMachineConfigSpec
$VMcfgSpec.Tools = New-Object VMware.Vim.ToolsConfigInfo
$VMcfgSpec.Tools.toolsUpgradePolicy = "upgradeAtPowerCycle"

# Go through all the VM's and update
$count = 0
foreach ($vm in $vms) {
    $count ++
    Write-Progress -Activity "Applying 'upgradeAtPowerCycle' setting to VMs" -Status ("Updating " + $vm.Name) -PercentComplete ($count/($vms.count)*100)
    
    # Get current setting
    $vmView = Get-View $vm -Property Config.Tools.ToolsUpgradePolicy
    # Change if setting isn't as we want
    if ($vmview.Config.Tools.ToolsUpgradePolicy -ne $UpgradePolicy) {
        $vmView.ReconfigVM($VMcfgSpec)
    }
}

Write-Host "Job done!"