######################################
YOU CAN RUN THESE SCRIPTS MANUALLY OR
RUN THE START UPDATE SECTION AS A 
SCHEDULED TASK AND THE FINISH SECTION
AS A SEPARATE TASK.
######################################

###	START UPDATE OF VM TEMPLATE ###
#Import the PowerCLI module
Add-PSSnapin VMware.VimAutomation.Core

#Host IP or vCenter Server IP/NAME
$hostIP = '[vCenter Server]'

#Connect to vCenter
Connect-VIServer $hostIP

#VM Templates to Update
$VMTemplates = 'Win7ENTx64','WS2012StdR2'

Foreach($vm in $VMTemplates){

    #convert template to VM
    Get-Template -Name $vm | Set-Template -ToVM

    #Power on VM
    Start-VM -VM $vm
 }

#Disconnect From vCenter Server
Disconnect-VIServer $hostIP -Confirm:$false

####################################
###	FINISH UPDATE OF VM TEMPLATE ###

#Import the PowerCLI module
Add-PSSnapin VMware.VimAutomation.Core

#Host IP or vCenter Server IP/NAME
$hostIP = '[vCenter Server]'

#Connect to vCenter
Connect-VIServer $hostIP

#VM Templates to Update
$VMTemplates = 'Win7ENTx64','WS2012StdR2'

 foreach($vm in $VMTemplates){
    
    #check if VM is powered on
    $ison = Get-VM -Name $vm
    
    if($ison.PowerState -eq 'PoweredOn'){
        
        #Shutdown VM
        Get-VM -Name $vm | Shutdown-VMGuest -Confirm:$false

        #Wait for shutdown to complete
        Start-Sleep -Seconds 300

        #Convert VM back to a Template
        $tobeTemplate =  Get-VM $vm | Get-View
        $tobeTemplate.MarkAsTemplate()

        }

    }

#Disconnect From vCenter Server
Disconnect-VIServer $hostIP -Confirm:$false