###########################################################
# Check For Windows Updates, Then Install
# Aimed At Remote Monitoring And Management Solutions (RMM)
# LogMeIn Central, AVG Managed Workplace Et. al
###########################################################

######################################################
# Provide The Literal Path To Required System Binaries
######################################################
$cscriptBinary = "C:\Windows\System32\cscript.exe"
$scBinary = "C:\Windows\System32\sc.exe"
$netBinary = "C:\Windows\System32\net.exe"

#########################
# Supply checkUpdates.vbs
#########################
$vbsCheckUpdates = @"

'ServerSelection values
ssDefault = 0
ssManagedServer   = 1
ssWindowsUpdate   = 2
ssOthers          = 3

'InStr values
intSearchStartChar = 1


dim strTitle


Set updateSession = CreateObject("Microsoft.Update.Session")
Set updateSearcher = updateSession.CreateupdateSearcher()

updateSearcher.ServerSelection = ssWindowsUpdate
Set searchResult = updateSearcher.Search("IsInstalled=0 and Type='Software'")

WScript.Echo "List of applicable items on the machine:"

For I = 0 To searchResult.Updates.Count-1
    Set update = searchResult.Updates.Item(I)
    WScript.Echo I + 1 & "> " & update.Title
Next

If searchResult.Updates.Count = 0 Then
    WScript.Echo "There are no applicable updates."
    WScript.Quit
End If

WScript.Echo vbCRLF & "Creating collection of updates to download:"

Set updatesToDownload = CreateObject("Microsoft.Update.UpdateColl")

For I = 0 to searchResult.Updates.Count-1
    Set update = searchResult.Updates.Item(I)
    addThisUpdate = false
    If update.InstallationBehavior.CanRequestUserInput = true Then
        WScript.Echo I + 1 & "> skipping: " & update.Title & _
        " because it requires user input"
    Else
        If update.EulaAccepted = false Then
            WScript.Echo I + 1 & "> note: " & update.Title & _
            " has a license agreement that must be accepted:"
            WScript.Echo update.EulaText
            WScript.Echo "Do you accept this license agreement? (Y/N)"
            ''strInput = WScript.StdIn.ReadLine
            strInput = "Y"
            WScript.Echo 
            If (strInput = "Y" or strInput = "y") Then
                update.AcceptEula()
                addThisUpdate = true
            Else
                WScript.Echo I + 1 & "> skipping: " & update.Title & _
                " because the license agreement was declined"
            End If
        Else
            addThisUpdate = true
        End If
    End If
    If addThisUpdate = true Then
        WScript.Echo I + 1 & "> adding: " & update.Title 
        updatesToDownload.Add(update)
    End If
Next

If updatesToDownload.Count = 0 Then
    WScript.Echo "All applicable updates were skipped."
    WScript.Quit
End If
    
WScript.Echo vbCRLF & "Downloading updates..."

Set downloader = updateSession.CreateUpdateDownloader() 
downloader.Updates = updatesToDownload
downloader.Download()

Set updatesToInstall = CreateObject("Microsoft.Update.UpdateColl")

rebootMayBeRequired = false

WScript.Echo vbCRLF & "Successfully downloaded updates:"

For I = 0 To searchResult.Updates.Count-1
    set update = searchResult.Updates.Item(I)
    If update.IsDownloaded = true Then
        WScript.Echo I + 1 & "> " & update.Title 
        updatesToInstall.Add(update)	
        If update.InstallationBehavior.RebootBehavior > 0 Then
            rebootMayBeRequired = true
        End If
    End If
Next

If updatesToInstall.Count = 0 Then
    WScript.Echo "No updates were successfully downloaded."
    WScript.Quit
End If

If rebootMayBeRequired = true Then
    WScript.Echo vbCRLF & "These updates may require a reboot."
End If

WScript.Echo  vbCRLF & "Would you like to install updates now? (Y/N)"
''strInput = WScript.StdIn.ReadLine
strInput = "Y"
WScript.Echo 

If (strInput = "Y" or strInput = "y") Then
    WScript.Echo "Installing updates..."
    Set installer = updateSession.CreateUpdateInstaller()
    installer.Updates = updatesToInstall
    Set installationResult = installer.Install()
	
    'Output results of install
    WScript.Echo "Installation Result: " & _
    installationResult.ResultCode 
    WScript.Echo "Reboot Required: " & _ 
    installationResult.RebootRequired & vbCRLF 
    WScript.Echo "Listing of updates installed " & _
    "and individual installation results:" 
	
    For I = 0 to updatesToInstall.Count - 1
        WScript.Echo I + 1 & "> " & _
        updatesToInstall.Item(i).Title & _
        ": " & installationResult.GetUpdateResult(i).ResultCode 		
    Next
End If

'ServerSelection values


' START NOTES

' Reference:
' <https://gallery.technet.microsoft.com/scriptcenter/VB-Script-to-Check-and-620579cd>

' END NOTES

"@

###########################
# Supply enableOptional.vbs
###########################
$vbsEnableOptional = @"

Set ServiceManager = CreateObject("Microsoft.Update.ServiceManager")
ServiceManager.ClientApplicationID = "My App"

'add the Microsoft Update Service, GUID
Set NewUpdateService = ServiceManager.AddService2("7971f918-a847-4430-9279-4a52d1efe18d",7,"")

' START NOTES

' Reference:
' <https://docs.microsoft.com/en-gb/windows/desktop/Wua_Sdk/opt-in-to-microsoft-update>
' <https://blogs.technet.microsoft.com/danbuche/2010/01/06/enabling-and-disabling-microsoft-update-in-windows-7-via-script/>

' END NOTES

"@

#######################
# Write Out *.vbs Files
#######################
$vbsCheckUpdates | Out-File checkUpdates.vbs -Force
$vbsEnableOptional | Out-File enableOptional.vbs -Force

###########################
# Enable 'wuauserv' Service
###########################
& $scBinary config wuauserv start= auto
& $netBinary start wuauserv

###############################
# Interpret Written *.vbs Files
###############################
& $cscriptBinary enableOptional.vbs
& $cscriptBinary checkUpdates.vbs

######################
# Clean-Up *.vbs Files
######################
Remove-Item .\enableOptional.vbs -Force 
Remove-Item .\checkUpdates.vbs -Force

#############
# START NOTES
#############

## You Must Run This PowerShell Script As An Administrator.
## Leverages 'Here-Strings' To Output The Self-Contained VBScript(s).
## In Future, Instead Of Writing Out To A File, Perhaps VBScript(s) Can Be Piped Directly To The Interpreter.

## Use 'C:\Windows\System32\where.exe' To Find Literal Binary Paths.
##
## OR
##
## 'Get-Command'.

###########
# END NOTES
###########