Powershell - Security installers on new VM build (VM customization)

<#
 .SYNOPSIS
  Script to install required apps to a recently deployed VM template

 .DESCRIPTION
  This script installs required applications to a newly deployed server.
  It's executed from the VM deployment scripts in vCenter.

 .NOTES

#>

#--------------------------------
# Variables
#--------------------------------
$InstallersDir = "\\VMAUTOserver\Installers"
$WorkingDir = "C:\VMTemplateDeploymentTemp"


#--------------------------------
# Create temp working directory
#--------------------------------
Write-Host "Creating $WorkingDir"
New-Item -ItemType directory -Path "$WorkingDir"


#--------------------------------
# Copy installers
#--------------------------------
Write-Host "Copying Red Cloak Installer to working directory."
Copy-Item "$InstallersDir\redcloak.msi" -Destination "$WorkingDir"

Write-Host "Copying Cisco Amp Installer to working directory."
Copy-Item "$InstallersDir\amp_Server.exe" -Destination "$WorkingDir"


#--------------------------------
# Install Apps
#--------------------------------
### Install Red Cloak
Write-Host "Installing Red Cloak"
Start-Process -FilePath "msiexec.exe" -ArgumentList "/i `"$WorkingDir\redcloak.msi`" /qn /passive" -Wait


### Install Cisco AMP with Server Policy
Write-Host "Installing Cisco Amp"
Start-Process -FilePath "$WorkingDir\amp_Server.exe" -ArgumentList '/S'

### Wait for the Cisco amp service to be created and running
$AmpService = "CiscoAmp*"
If ((Get-Service $AmpService).Status -ne 'Running') {
   do {
       Write-Host 'Waiting for Cisco Amp service to be created and get to a Running state.'
       Start-Sleep 5
   } until ((Get-Service $AmpService).Status -eq 'Running')
}
Write-Host "Cisco Amp service has STARTED"
Start-Sleep -seconds 5


#--------------------------------
# Clean it all up
#--------------------------------
Write-Host "Cleaning up and deleting installers from C:"
#Remove-Item -Path "$WorkingDir\amp_Server.exe"
#Remove-Item -Path "$WorkingDir\redcloak.msi"
Remove-Item -LiteralPath "$WorkingDir\" -Recurse -Force


#--------------------------------
# Windows Updates
#--------------------------------
### Check if PSWindowsUpdate module exists. Install if not.
if (Get-Module -ListAvailable -Name PSWindowsUpdate) {
    Write-Host "PSWindowsUpdate module exists."
} else {
    Write-Host "PSWindowsUpdate module does not exist. Installing now."
    Install-Module -Name PSWindowsUpdate -Force
}

Write-Host "Windows Updates - Installing all..."
Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot

# Clean up the WinSxS component store and optimize the image with DISM
Write-Host "Cleaning up the WinSxS component store and optimizing the image with DISM"
Dism.exe /Online /Cleanup-Image /StartComponentCleanup /ResetBase

#--------------------------------
# Reboot Server
#--------------------------------
Write-Host "Rebooting $env:computername"
shutdown.exe /r /t 60