Powershell script to replace the Microsoft Windows interface by your own app.

Why the hell would you like to replace the Windows shell? If the answer is “to replace it with my own app”, let’s do this.

Here is the Shell script to run in a PowerShell with admin account in god mode. Copy / Paste / Save in a textfile, rename the file with myawesomescript.ps1

# Check if shell launcher license is enabled
function Check-ShellLauncherLicenseEnabled
{
    [string]$source = @"
using System;
using System.Runtime.InteropServices;

static class CheckShellLauncherLicense
{
    const int S_OK = 0;

    public static bool IsShellLauncherLicenseEnabled()
    {
        int enabled = 0;

        if (NativeMethods.SLGetWindowsInformationDWORD("EmbeddedFeature-ShellLauncher-Enabled", out enabled) != S_OK) {
            enabled = 0;
        }

        return (enabled != 0);
    }

    static class NativeMethods
    {
        [DllImport("Slc.dll")]
        internal static extern int SLGetWindowsInformationDWORD([MarshalAs(UnmanagedType.LPWStr)]string valueName, out int value);
    }

}
"@

    $type = Add-Type -TypeDefinition $source -PassThru

    return $type[0]::IsShellLauncherLicenseEnabled()
}

[bool]$result = $false

$result = Check-ShellLauncherLicenseEnabled
"`nShell Launcher license enabled is set to " + $result
if (-not($result))
{
    "`nThis device doesn't have required license to use Shell Launcher"
    exit
}

$COMPUTER = "localhost"
$NAMESPACE = "root\standardcimv2\embedded"

# Create a handle to the class instance so we can call the static methods.
try {
    $ShellLauncherClass = [wmiclass]"\\$COMPUTER\${NAMESPACE}:WESL_UserSetting"
    } catch [Exception] {
    write-host $_.Exception.Message; 
    write-host "Make sure Shell Launcher feature is enabled"
    exit
    }


# This well-known security identifier (SID) corresponds to the BUILTIN\Administrators group.

$Admins_SID = "S-1-5-32-544"

# Create a function to retrieve the SID for a user account on a machine.

function Get-UsernameSID($AccountName) {

    $NTUserObject = New-Object System.Security.Principal.NTAccount($AccountName)
    $NTUserSID = $NTUserObject.Translate([System.Security.Principal.SecurityIdentifier])

    return $NTUserSID.Value

}

# Get the SID for a user account named "Cashier". Rename "Cashier" to an existing account on your system to test this script. In this case, I renamed it to KIOSK.

$Cashier_SID = Get-UsernameSID("KIOSK")

# Define actions to take when the shell program exits.

$restart_shell = 0
$restart_device = 1
$shutdown_device = 2

# Examples. You can change these examples to use the program that you want to use as the shell.

# This example sets the command prompt as the default shell, and restarts the device if the command prompt is closed. 

# $ShellLauncherClass.SetDefaultShell("C:\MyAwesomeApp.exe", $restart_shell)

# Display the default shell to verify that it was added correctly.

$DefaultShellObject = $ShellLauncherClass.GetDefaultShell()

"`nDefault Shell is set to " + $DefaultShellObject.Shell + " and the default action is set to " + $DefaultShellObject.defaultaction

# Set MyAwesomeApp.exe as the shell for "Cashier", and restart the machine if the app is closed (or crashed).

$ShellLauncherClass.SetCustomShell($Cashier_SID, "C:\MyAwesomeApp.exe", ($null), ($null), $restart_shell)

# Set Explorer as the shell for administrators.

$ShellLauncherClass.SetCustomShell($Admins_SID, "explorer.exe")

# View all the custom shells defined.

"`nCurrent settings for custom shells:"
Get-WmiObject -namespace $NAMESPACE -computer $COMPUTER -class WESL_UserSetting | Select Sid, Shell, DefaultAction

# Enable Shell Launcher

$ShellLauncherClass.SetEnabled($TRUE)

$IsShellLauncherEnabled = $ShellLauncherClass.IsEnabled()

"`nEnabled is set to " + $IsShellLauncherEnabled.Enabled

# Remove the new custom shells.

# $ShellLauncherClass.RemoveCustomShell($Admins_SID)

# $ShellLauncherClass.RemoveCustomShell($Cashier_SID)

# Disable Shell Launcher

# $ShellLauncherClass.SetEnabled($FALSE)

$IsShellLauncherEnabled = $ShellLauncherClass.IsEnabled()

"`nEnabled is set to " + $IsShellLauncherEnabled.Enabled

Within the PowerShell console, go to the folder with this script then execute the script:

PS> cd C:\MyFolder\WhereIsBrian\
PS> .\myawesomescript.ps1 (enter)

Here you are :)

Written on July 12, 2017