The WScript.Shell Class - a way to interact with an active Window via PowerShell

by Thomas Bründl

This article has not been completed yet. However, it may already contain helpful Information and therefore it has been published at this stage.

The WScript.Shell class provides a set of useful utilities that greatly expand the range of tasks that can be performed with Windows PowerShell and COM.

  • Running applications
  • Sending keyboard input to running applications
  • Changing the current working directory
  • Displaying pop-up message dialog boxes
  • ......

The list of available methods and properties is displayed as follows:

# Creating WScript.Shell Object
$wscript = new-object -com wscript.shell

# Displaying all available object properties / methods
$wscript | gm


   TypeName: System.__ComObject#{41904400-be18-11d3-a28b-00104bd35090}

Name                     MemberType            Definition
----                     ----------            ----------
AppActivate              Method                bool AppActivate (Variant, Variant)
CreateShortcut           Method                IDispatch CreateShortcut (string)
Exec                     Method                IWshExec Exec (string)
ExpandEnvironmentStrings Method                string ExpandEnvironmentStrings (string)
LogEvent                 Method                bool LogEvent (Variant, string, string)
Popup                    Method                int Popup (string, Variant, Variant, Variant)
RegDelete                Method                void RegDelete (string)
RegRead                  Method                Variant RegRead (string)
RegWrite                 Method                void RegWrite (string, Variant, Variant)
Run                      Method                int Run (string, Variant, Variant)
SendKeys                 Method                void SendKeys (string, Variant)
Environment              ParameterizedProperty IWshEnvironment Environment (Variant) {get}
CurrentDirectory         Property              string CurrentDirectory () {get} {set}
SpecialFolders           Property              IWshCollection SpecialFolders () {get}

The power of the WScript.Shell class is best demonstrated through  a simple example. The following script launches an  application, waits until the application has started to make it  the active application (such that the focus is on the application) and  then sends some keys and text to the application.

To be honest, I used it to automate the establishment of a VPN connection. I strongly recommend not to store passwords (as done in this code snippet below) in plain text in a script. A good way to handle passwords can be found here - Link

# Start a Process
$ps = Start-Process -PassThru -FilePath "<FilePath>" -WindowStyle "<Normal|Hidden|Minimized|Maximized>"

# Creating WScript.Shell instance
$wshell = New-Object -ComObject wscript.shell

# Wait until activating the target process succeeds.
# Note: You may want to implement a timeout here.
while (-not $wshell.AppActivate($ps.Id)) {
  
  # Waiting for app to start....
  # Start-Sleep -MilliSeconds 200
}

$wshell.SendKeys('~')
Sleep 3
$wshell.SendKeys('username')
Sleep 2
$wshell.SendKeys('{TAB}')
Sleep 1
$wshell.SendKeys('password')

References:

https://www.techotopia.com/index.php?title=Using_COM_with_Windows_PowerShell_1.0&mobileaction=toggle_view_mobile

How to use the Secret modules - PowerShell Community (microsoft.com)