PowerShell: Disable Windows Defender

# removeWindowsDefender.ps1
# Version 0.02

$computerNames=@(
  'server1',
  'server2'
)

function removeWindowsDefender($computerNames){
  function uninstallWindefend($computername){
    $session=try{
      New-PSSession $computername -EA Stop
    }catch{
      New-PSSession $computername -SessionOption (New-PSSessionOption -IncludePortInSPN)
    }
    if($session.state -eq 'opened'){
      $result=invoke-command -Session $session -scriptblock{
        $serverOs=(Get-WmiObject Win32_OperatingSystem).Name -match "^Microsoft Windows Server"
        $null=Set-MpPreference -DisableRealtimeMonitoring $True -EA SilentlyContinue
        if($serverOs){          
          $null=Remove-WindowsFeature Windows-Defender-GUI -EA SilentlyContinue
          $null=Remove-WindowsFeature Windows-Defender -EA SilentlyContinue
          return [hashtable]@{$env:computername=(Get-WindowsFeature windows-defender).InstallState -ne 'Installed'}
        }else{
          return [hashtable]@{$env:computername=(Get-MpComputerStatus).AntivirusEnabled -ne $true}
        }       
      }
      Remove-PSSession $session
    }else{
      write-warning "cannot connect to $computername via WinRM"
      $result=[hashtable]@{$env:computername='Unknown'}
    }
    return $result
  }

  $timer=[System.Diagnostics.Stopwatch]::StartNew()
  $jobResults=@()
  $lineBreak=60
  $dotCount=0
  $minute=0
  $processorsCount=(Get-CimInstance Win32_ComputerSystem).NumberOfLogicalProcessors
  $cpuLoad=(Get-WmiObject win32_processor|Measure-Object -property LoadPercentage -Average).Average
  $maxSimultaneousJobs=if($cpuLoad -gt 90){$processorsCount}else{($processorsCount*2)-1} # dynamically limiting concurrent jobs basing on available CPU cores
  write-host "CPU load detected as: $cpuLoad`%`r`nSetting concurrent jobs max count to be $maxSimultaneousJobs"
  foreach($computerName in $computerNames){
      $thisIterationCompleted=$false
      do {
          $jobsCount=(Get-Job -State 'Running').Count
          if ($jobsCount -lt $maxSimultaneousJobs){            
              if($verbose){write-host "Initiating job for $computerName"}
              $null=Start-Job -name $computerName -ScriptBlock {
                  param($uninstallWindefend,$computerName)
                  [scriptblock]::create($uninstallWindefend).invoke($computerName)
              } -Args ${function:uninstallWindefend},$computerName
              $thisIterationCompleted=$true
          }else{
              if($verbose){
                  if($dotCount++ -lt $lineBreak){
                      write-host '.' -NoNewline
                  }else{
                      $minute++
                      write-host "`r`n$minute`t:" -ForegroundColor Yellow -NoNewline
                      $dotCount=0
                      }
              }
              sleep -seconds 1
          }
      }until ($thisIterationCompleted)
  }
  $totalJobsCount=(get-job).count
  $processedCount=0
  while($processedCount -lt $totalJobsCount){
      $completedJobs=get-job|?{$_.State -eq 'Completed'}
      if($completedJobs){
          foreach ($job in $completedJobs){
              $computer=$job.Name
              if($verbose){
                  write-host "`r`n===================================================`r`n$computer job completed with these messages:`r`n===================================================`r`n"
              }
              $jobResult=receive-job -id $job.id
              $jobResults+=,$jobResult
              remove-job -id $job.id -force
              $processedCount++
          }
      }
  }
  $minutesElapsed=[math]::round($timer.Elapsed.TotalMinutes,2)
  $timer.stop()
  write-host "$($computerNames.count) computers were processed in $minutesElapsed minutes."
  return $jobResults #|select -property * -excludeproperty RunspaceId
}

removeWindowsDefender $computerNames

Remove-WindowsFeature : The request to add or remove features on the specified server failed.
Removal of one or more roles, role services, or features failed.
The referenced assembly could not be found. Error: 0x80073701
    + CategoryInfo          : InvalidOperation: (@{Vhd=; Credent...Name=localhost}:PSObject) [Uninstall-WindowsFeature
   ], Exception
    + FullyQualifiedErrorId : DISMAPI_Error__Failed_Disabling_Updates,Microsoft.Windows.ServerManager.Commands.RemoveW
   indowsFeatureCommand

Success Restart Needed Exit Code      Feature Result
------- -------------- ---------      --------------
False   No             Failed         {}

# removeWindowsDefender.ps1
# Version 0.01
$computerNames=@(
  'server1',
  'server2'
)

function removeWindowsDefender($computerNames){
  $results=@()
  foreach($computername in $computernames){
    write-host "Checking $computername..."
    $session=try{
      New-PSSession $computername -EA Stop
    }catch{
      New-PSSession $computername -SessionOption (New-PSSessionOption -IncludePortInSPN)
    }
    if($session.state -eq 'opened'){
      $result=invoke-command -Session $session -scriptblock{
        $null=Set-MpPreference -DisableRealtimeMonitoring $True -EA SilentlyContinue
        $null=Remove-WindowsFeature Windows-Defender-GUI -EA SilentlyContinue
        $null=Remove-WindowsFeature Windows-Defender -EA SilentlyContinue
        return [hashtable]@{$env:computername=(Get-WindowsFeature windows-defender).InstallState -ne 'Installed'}
      }
      Remove-PSSession $session
    }else{
      write-warning "cannot connect to $computername via WinRM"
      $result=[hashtable]@{$env:computername='Unknown'}
    }
    $results+=$result
  }
}

removeWindowsDefender $computerNames