2012.json:

{
    "variables": {
        "source_ami": "{{env `AMI`}}",
        "ami_users": "{{env `ACCOUNT`}}",
        "snapshot_users": "{{env `ACCOUNT`}}"
    },
    "builders": [{
        "type": "amazon-ebs",
        "region": "us-east-1",
        "source_ami": "{{user `source_ami`}}",
        "instance_type": "m3.medium",
        "user_data_file": "./ec2-userdata.ps1",
        "iam_instance_profile": "Packer",
        "ami_users": "{{user `ami_users`}}",
        "snapshot_users": "{{user `snapshot_users`}}",
        "ami_name": "2012 R2 TEST {{timestamp}}",
        "communicator": "winrm",
        "winrm_username": "Administrator",
        "winrm_use_ssl": true,
        "winrm_insecure": true
    }],
    "provisioners": [
        {
    "type": "powershell",
    "environment_vars": "WINRMPASS={{.WinRMPassword}}",
    "elevated_user": "Administrator",
    "elevated_password": "{{.WinRMPassword}}",
    "script": "install-updates-2012.ps1"
}
    ]
    }


ec2-userdata:
<powershell>
write-output "Running User Data Script"
write-host "(host) Running User Data Script"
Set-ExecutionPolicy Unrestricted -Scope LocalMachine -Force -ErrorAction Ignore
# Don't set this before Set-ExecutionPolicy as it throws an error
$ErrorActionPreference = "stop"
# Remove HTTP listener
Remove-Item -Path WSMan:\Localhost\listener\listener* -Recurse
$Cert = New-SelfSignedCertificate -CertstoreLocation Cert:\LocalMachine\My -DnsName "packer"
New-Item -Path WSMan:\LocalHost\Listener -Transport HTTPS -Address * -CertificateThumbPrint $Cert.Thumbprint -Force
# WinRM
write-output "Setting up WinRM"
write-host "(host) setting up WinRM"
cmd.exe /c winrm quickconfig -q
cmd.exe /c winrm set "winrm/config" '@{MaxTimeoutms="1800000"}'
cmd.exe /c winrm set "winrm/config/winrs" '@{MaxMemoryPerShellMB="1024"}'
cmd.exe /c winrm set "winrm/config/service" '@{AllowUnencrypted="true"}'
cmd.exe /c winrm set "winrm/config/client" '@{AllowUnencrypted="true"}'
cmd.exe /c winrm set "winrm/config/service/auth" '@{Basic="true"}'
cmd.exe /c winrm set "winrm/config/client/auth" '@{Basic="true"}'
cmd.exe /c winrm set "winrm/config/service/auth" '@{CredSSP="true"}'
cmd.exe /c winrm set "winrm/config/listener?Address=*+Transport=HTTPS" "@{Port=`"5986`";Hostname=`"packer`";CertificateThumbprint=`"$($Cert.Thumbprint)`"}"
cmd.exe /c netsh advfirewall firewall set rule group="remote administration" new enable=yes
cmd.exe /c netsh firewall add portopening TCP 5986 "Port 5986"
cmd.exe /c net stop winrm
cmd.exe /c sc config winrm start= auto
cmd.exe /c net start winrm
</powershell>

install-updates-2012.ps1
param($global:RestartRequired=0,
        $global:MoreUpdates=0,
        $global:MaxCycles=5,
        $MaxUpdatesPerCycle=500)

$Logfile = "C:\Windows\Temp\WindowsUpdate.log"

function LogWrite {
   Param ([string]$logstring)
   $now = Get-Date -format s
   Add-Content $Logfile -value "$now $logstring"
   Write-Host $logstring
}

function Check-ContinueRestartOrEnd() {
    $RegistryKey = "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run"
    $RegistryEntry = "InstallWindowsUpdates"
    switch ($global:RestartRequired) {
        0 {
            $prop = (Get-ItemProperty $RegistryKey).$RegistryEntry
            if ($prop) {
                LogWrite "Restart Registry Entry Exists - Removing It"
                Remove-ItemProperty -Path $RegistryKey -Name $RegistryEntry -ErrorAction SilentlyContinue
            }

            LogWrite "No Restart Required"
            Check-WindowsUpdates

            if (($global:MoreUpdates -eq 1) -and ($script:Cycles -le $global:MaxCycles)) {
                Install-WindowsUpdates
            } elseif ($script:Cycles -gt $global:MaxCycles) {
                LogWrite "Exceeded Cycle Count - Stopping"
            } else {
                LogWrite "Done Installing Windows Updates"
            }
        }
        1 {
            $prop = (Get-ItemProperty $RegistryKey).$RegistryEntry
            if (-not $prop) {
                LogWrite "Restart Registry Entry Does Not Exist - Creating It"
                Set-ItemProperty -Path $RegistryKey -Name $RegistryEntry -Value "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -File $($script:ScriptPath) -MaxUpdatesPerCycle $($MaxUpdatesPerCycle)"
            } else {
                LogWrite "Restart Registry Entry Exists Already"
            }

            LogWrite "Restart Required - Restarting..."
            Restart-Computer
        }
        default {
            LogWrite "Unsure If A Restart Is Required"
            break
        }
    }
}

function Install-WindowsUpdates() {
    $script:Cycles++
    LogWrite "Evaluating Available Updates with limit of $($MaxUpdatesPerCycle):"
    $UpdatesToDownload = New-Object -ComObject 'Microsoft.Update.UpdateColl'
    $script:i = 0;
    $CurrentUpdates = $SearchResult.Updates
    while($script:i -lt $CurrentUpdates.Count -and $script:CycleUpdateCount -lt $MaxUpdatesPerCycle) {
        $Update = $CurrentUpdates.Item($script:i)
        if (($Update -ne $null) -and (!$Update.IsDownloaded)) {
            [bool]$addThisUpdate = $false
            if ($Update.InstallationBehavior.CanRequestUserInput) {
                LogWrite "> Skipping: $($Update.Title) because it requires user input"
            } else {
                if (!($Update.EulaAccepted)) {
                    LogWrite "> Note: $($Update.Title) has a license agreement that must be accepted. Accepting the license."
                    $Update.AcceptEula()
                    [bool]$addThisUpdate = $true
                    $script:CycleUpdateCount++
                } else {
                    [bool]$addThisUpdate = $true
                    $script:CycleUpdateCount++
                }
            }

            if ([bool]$addThisUpdate) {
                LogWrite "Adding: $($Update.Title)"
                $UpdatesToDownload.Add($Update) |Out-Null
            }
        }
        $script:i++
    }

    if ($UpdatesToDownload.Count -eq 0) {
        LogWrite "No Updates To Download..."
    } else {
        LogWrite 'Downloading Updates...'
        $ok = 0;
        while (! $ok) {
            try {
                $Downloader = $UpdateSession.CreateUpdateDownloader()
                $Downloader.Updates = $UpdatesToDownload
                $Downloader.Download()
                $ok = 1;
            } catch {
                LogWrite $_.Exception | Format-List -force
                LogWrite "Error downloading updates. Retrying in 30s."
                $script:attempts = $script:attempts + 1
                Start-Sleep -s 30
            }
        }
    }

    $UpdatesToInstall = New-Object -ComObject 'Microsoft.Update.UpdateColl'
    [bool]$rebootMayBeRequired = $false
    LogWrite 'The following updates are downloaded and ready to be installed:'
    foreach ($Update in $SearchResult.Updates) {
        if (($Update.IsDownloaded)) {
            LogWrite "> $($Update.Title)"
            $UpdatesToInstall.Add($Update) |Out-Null

            if ($Update.InstallationBehavior.RebootBehavior -gt 0){
                [bool]$rebootMayBeRequired = $true
            }
        }
    }

    if ($UpdatesToInstall.Count -eq 0) {
        LogWrite 'No updates available to install...'
        $global:MoreUpdates=0
        $global:RestartRequired=0
        break
    }

    if ($rebootMayBeRequired) {
        LogWrite 'These updates may require a reboot'
        $global:RestartRequired=1
    }

    LogWrite 'Installing updates...'

    $Installer = $script:UpdateSession.CreateUpdateInstaller()
    $Installer.Updates = $UpdatesToInstall
    $InstallationResult = $Installer.Install()

    LogWrite "Installation Result: $($InstallationResult.ResultCode)"
    LogWrite "Reboot Required: $($InstallationResult.RebootRequired)"
    LogWrite 'Listing of updates installed and individual installation results:'
    if ($InstallationResult.RebootRequired) {
        $global:RestartRequired=1
    } else {
        $global:RestartRequired=0
    }

    for($i=0; $i -lt $UpdatesToInstall.Count; $i++) {
        New-Object -TypeName PSObject -Property @{
            Title = $UpdatesToInstall.Item($i).Title
            Result = $InstallationResult.GetUpdateResult($i).ResultCode
        }
        LogWrite "Item: $($UpdatesToInstall.Item($i).Title)"
        LogWrite "Result: $($InstallationResult.GetUpdateResult($i).ResultCode)"
    }

    Check-ContinueRestartOrEnd
}

function Check-WindowsUpdates() {
    LogWrite "Checking For Windows Updates"
    $Username = $env:USERDOMAIN + "\" + $env:USERNAME

    New-EventLog -Source $ScriptName -LogName 'Windows Powershell' -ErrorAction SilentlyContinue

    $Message = "Script: " + $ScriptPath + "`nScript User: " + $Username + "`nStarted: " + (Get-Date).toString()

    Write-EventLog -LogName 'Windows Powershell' -Source $ScriptName -EventID "104" -EntryType "Information" -Message $Message
    LogWrite $Message

    $script:UpdateSearcher = $script:UpdateSession.CreateUpdateSearcher()
    $script:successful = $FALSE
    $script:attempts = 0
    $script:maxAttempts = 12
    while(-not $script:successful -and $script:attempts -lt $script:maxAttempts) {
        try {
            $script:SearchResult = $script:UpdateSearcher.Search("IsInstalled=0 and Type='Software' and IsHidden=0")
            $script:successful = $TRUE
        } catch {
            LogWrite $_.Exception | Format-List -force
            LogWrite "Search call to UpdateSearcher was unsuccessful. Retrying in 10s."
            $script:attempts = $script:attempts + 1
            Start-Sleep -s 10
        }
    }

    if ($SearchResult.Updates.Count -ne 0) {
        $Message = "There are " + $SearchResult.Updates.Count + " more updates."
        LogWrite $Message
        try {
            for($i=0; $i -lt $script:SearchResult.Updates.Count; $i++) {
              LogWrite $script:SearchResult.Updates.Item($i).Title
              LogWrite $script:SearchResult.Updates.Item($i).Description
              LogWrite $script:SearchResult.Updates.Item($i).RebootRequired
              LogWrite $script:SearchResult.Updates.Item($i).EulaAccepted
          }
            $global:MoreUpdates=1
        } catch {
            LogWrite $_.Exception | Format-List -force
            LogWrite "Showing SearchResult was unsuccessful. Rebooting."
            $global:RestartRequired=1
            $global:MoreUpdates=0
            Check-ContinueRestartOrEnd
            LogWrite "Show never happen to see this text!"
            Restart-Computer
        }
    } else {
        LogWrite 'There are no applicable updates'
        $global:RestartRequired=0
        $global:MoreUpdates=0
    }
}

$script:ScriptName = $MyInvocation.MyCommand.ToString()
$script:ScriptPath = $MyInvocation.MyCommand.Path
$script:UpdateSession = New-Object -ComObject 'Microsoft.Update.Session'
$script:UpdateSession.ClientApplicationID = 'Packer Windows Update Installer'
$script:UpdateSearcher = $script:UpdateSession.CreateUpdateSearcher()
$script:SearchResult = New-Object -ComObject 'Microsoft.Update.UpdateColl'
$script:Cycles = 0
$script:CycleUpdateCount = 0

Check-WindowsUpdates
if ($global:MoreUpdates -eq 1) {
    Install-WindowsUpdates
} else {
    Check-ContinueRestartOrEnd
}




ERROR:

WinRM connected.
==> amazon-ebs: Connected to WinRM!
==> amazon-ebs: Provisioning with Powershell...
==> amazon-ebs: Provisioning with powershell script: install-updates-2012.ps1
    amazon-ebs: Exception calling "RegisterTaskDefinition" with "7" argument(s): "The user
    amazon-ebs: name or password is incorrect. (Exception from HRESULT: 0x8007052E)"
    amazon-ebs: At C:\Users\Administrator\AppData\Local\Temp\packer-elevated-shell-5adf6c79-801
    amazon-ebs: 1-c45a-030c-a5d7a7713f6c.ps1:49 char:1
    amazon-ebs: + $f.RegisterTaskDefinition($name, $t, 6, "Administrator", "<no value>", 1,
    amazon-ebs: $null) ...
    amazon-ebs: + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    amazon-ebs: ~~~
    amazon-ebs:     + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    amazon-ebs:     + FullyQualifiedErrorId : ComMethodTargetInvocation
    amazon-ebs:
    amazon-ebs: Exception calling "GetTask" with "1" argument(s): "The system cannot find the
    amazon-ebs: file specified. (Exception from HRESULT: 0x80070002)"
    amazon-ebs: At C:\Users\Administrator\AppData\Local\Temp\packer-elevated-shell-5adf6c79-801
    amazon-ebs: 1-c45a-030c-a5d7a7713f6c.ps1:50 char:1
    amazon-ebs: + $t = $f.GetTask("\$name")
    amazon-ebs: + ~~~~~~~~~~~~~~~~~~~~~~~~~
    amazon-ebs:     + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    amazon-ebs:     + FullyQualifiedErrorId : ComMethodTargetInvocation
    amazon-ebs:
    amazon-ebs: Method invocation failed because [System.__ComObject] does not contain a
    amazon-ebs: method named 'Run'.
    amazon-ebs: At C:\Users\Administrator\AppData\Local\Temp\packer-elevated-shell-5adf6c79-801
    amazon-ebs: 1-c45a-030c-a5d7a7713f6c.ps1:51 char:1
    amazon-ebs: + $t.Run($null) | Out-Null
    amazon-ebs: + ~~~~~~~~~~~~~~~~~~~~~~~~
    amazon-ebs:     + CategoryInfo          : InvalidOperation: (Run:String) [], RuntimeExcept
    amazon-ebs:    ion
    amazon-ebs:     + FullyQualifiedErrorId : MethodNotFound
    amazon-ebs: