param(
    [string]$Criteria = "IsInstalled=0 and Type='Software' and IsHidden=0",
    [switch]$RebootToComplete
)

function InstallationResultToText($result) {
  switch ($result) {
    2 { "Succeeded" }
    3 { "Succeeded with errors" }
    4 { "Failed" }
    5 { "Cancelled" }
    default { "Unexpected ($result)" }  
  }
}

#Write-Host "### Command line parameters you specify. ###"
#Write-Host "-Criteria:           $Criteria"
#Write-Host "-RebootToComplete:   $RebootToComplete"
#Write-Host ""

Write-Host "### Running Windows Update (for indivisual update) ###"
Write-Host "Searching for updates..."
Write-Host ""
$updateSession = new-object -com "Microsoft.Update.Session"
$updateSearcher = $updateSession.CreateupdateSearcher()
$searchResult = $updateSearcher.Search($criteria)

Write-Host "List of applicable items on the machine:"

if ($searchResult.Updates.Count -eq 0) {
  Write-Host "There are no applicable updates."
  exit 0
} else {
  $downloadReq = $False
  $i = 0
  foreach ($update in $searchResult.Updates){
    $i++
    if ( $update.IsDownloaded ) {
      Write-Host $i">" $update.Title "(downloaded)"
    } else {
      $downloadReq = $true
      Write-Host $i">" $update.Title "(not downloaded)"
    }
  }
}

Write-Host ""
if ($i -eq 1) {
  $response = Read-Host "1 update found. Do you want to install it ?(Y/N)"
} else {
  $response = Read-Host "Enter the number of the update you wish to install (Type C to abort)"
}

if ($response -match '^[Yy]$') {
} elseif ($response -match '^[Cc]$') {
  Write-Host "Aborted."
  exit 0
} elseif ($response -as [int]) {
  if ($response -gt $i) {
    Write-Host "Aborted."
    exit 0
  }
}
$targetupdatetitle = $searchResult.Updates.item($response - 1).Title

if ( $downloadReq ) {
  Write-Host "Creating collection of updates to download..."
  $updatesToDownload = new-object -com "Microsoft.Update.UpdateColl"
  foreach ($update in $searchResult.Updates){
    if ($update.Title -eq $targetupdatetitle) {
      $updatesToDownload.Add($update) | out-null
    }
  }
  Write-Host "Downloading updates..."
  $downloader = $updateSession.CreateUpdateDownloader()
  $downloader.Updates = $updatesToDownload
  $downloader.Download()
  Write-Host "List of downloaded updates:"
  $i = 0
  foreach ($update in $searchResult.Updates){
    $i++
    if ( $update.IsDownloaded ) {
      Write-Host $i">" $update.Title "(downloaded)"
    #} else {
    #  Write-Host $i">" $update.Title "(not downloaded)"
    }
  }
} else {
  Write-Host "All updates are already downloaded."
}

$updatesToInstall = new-object -com "Microsoft.Update.UpdateColl"
Write-Host ""
Write-Host "Creating collection of downloaded updates to install..."
foreach ($update in $searchResult.Updates){
  if ( $update.IsDownloaded ) {
    $updatesToInstall.Add($update) | out-null
  }
}
$returnValue = 1
if ( $updatesToInstall.Count -eq 0 ) {
  Write-Host "Not ready for installation."
} else {
  Write-Host "Installing" $updatesToInstall.Count "updates..."
  $installer = $updateSession.CreateUpdateInstaller()
  $installer.Updates = $updatesToInstall
  $installationResult = $installer.Install()
  if ( $installationResult.ResultCode -eq 2 ) {
    Write-Host "One update installed successfully."
  } else {
    Write-Host "Update could not installed."
  }
}
if ( $installationResult.RebootRequired ) {
     Write-Host "One update are requiring reboot."
} else {
     Write-Host "Finished. Reboot are not required."
}
Write-Host ""
Write-Host "Listing of updates installed and indivisual installation results:"
$i = 0
foreach ($update in $updatesToInstall){
    $result = $installationResult.GetUpdateResult($i)
    $i++
    Write-Host $i">" $update.Title ":" $(InstallationResultToText $result.ResultCode) ", HRESULT:" $($result.HResult)
  } 
if ($installationResult.RebootRequired) {
  if ($RebootToComplete) {
      Write-Host "After 60 seconds, the system will initiate a restart automatically. To abort , press Ctrl+C. (-RebootToComplete)"
      for ($i = 60; $i -gt 0; $i--) {
        Write-Host "." -NoNewLine
        Start-Sleep -Seconds 1
      }
      restart-Computer -Force
    } elseif (-not $Automate) {
    $response = Read-Host "Reboot is pending. Would you like to reboot? (Y/N)"
    if ($response -match '^[Yy]$') {
      Write-Host "Reboot now!..."
      sleep -Seconds 3
      restart-Computer -Force
    } else {
      Write-Host "You need to reboot this device later."
    }
  }
}
Exit $returnValue

$ScriptforSigleUpdatePath = ".\WUA_SearchDownloadInstallS.ps1"

...

if (-not $Automate ) {
  $response = Read-Host "Next step: download all updates(Y) or donload/install single update(S). May I continue? (Y/N/S)"
  if ($response -match '^[Yy]$') {
    Write-Host "Proceed to the next step: download all updates."
  } elseif ($response -match '^[Ss]$') {
    Write-Host "Proceed to the next step: download/install single update."
    If (Test-Path $ScriptforSigleUpdatePath) {
      . $ScriptforSigleUpdatePath
      exit $LASTEXITCODE
    } else {
      Write-Host "$ScriptforSigleUpdatePath not found."
      exit 0
    }
 ･･･