MDT: How to initiate a reboot during a task without corrupting the task sequence

Recently, I have been working on updating several scripts I have written for the build process. One big thing I have wanted is for the script to be able to initiate a reboot without the build process becoming corrupt. An additional functionality I have wanted to implement is to be able to restart the task sequence at the same point it left off before the reboot.

I knew the task sequence reruns the windows update process multiple times, so I started by looking at the ZTIWindowsUpdate.wsf file. While combing through the file, I found the two items used for this process. They are:

• SMSTSRebootRequested that reboots the machine
• SMSTSRetryRequested tells the script to rerun the same task. 

I wanted this to be written in PowerShell, so next was figuring out how to access these two MDT environmental variables. After researching, I found that I can load the comobject Microsoft.SMS.TSEnvironment and that will give access to them. The following three lines of code are all that is needed in a PowerShell script to initiate a reboot and/or rerun the same task once it completes. Setting the above-listed variables to $true is what is required. If you just want to rerun the same task, you are not required to initiate the reboot. Once the task is completed, it will rerun again if SMSTSRetryRequested is specified at the end. 

      $TaskSequence = New-Object -ComObject Microsoft.SMS.TSEnvironment  
      #Reboot the machine this command line task sequence finishes  
      $TaskSequence.Value('SMSTSRebootRequested') = $true  
      #Rerun this task when the reboot finishes  
      $TaskSequence.Value('SMSTSRetryRequested') = $true