Configures developer mode and installs WSL feature

Enable-UbuntuForWindows.ps1

#Requires -RunAsAdministrator

<#
.SYNOPSIS
    Enable Windows Subsystem for Linux (Ubuntu) on Windows 10 version 1607 or later.
 
.DESCRIPTION
    This script will configure Developer Mode in order to enable Windows Subsystem for Linux (Ubuntu) on Windows 10 version 1607 or later.
 
.EXAMPLE
    Prepare Windows 10 for Windows Subsystem for linux and install required features:
    .\Enable-UbuntuForWindows.ps1
    powershell -nop -c "iex(New-Object Net.WebClient).DownloadString('https://goo.gl/dDX8GR')"
 
.NOTES
    FileName:         Enable-UbuntuForWindows.ps1
    Maintainer:       Richard Drake <richard.drake@uoit.ca>
    Original Author:  Nickolaj Andersen (@NickolajA)
    Created:          2016-09-08
    Updated:          2017-09-19
     
    Version history:
    1.0.0 - (2016-09-08) Script created
    1.1.0 - (2017-09-19) Script cleaned up and modified to support non-SCCM deployment
#>

# https://stackoverflow.com/questions/37352912/how-to-return-true-false-to-get-windowsoptionalfeature-on-windows-10
function Check-WindowsFeature {
    [CmdletBinding()]
    param(
        [Parameter(Position=0,Mandatory=$true)] [string]$FeatureName
    )
    if((Get-WindowsOptionalFeature -FeatureName $FeatureName -Online).State -eq "Enabled") {
        Write-Warning -Message "$FeatureName already enabled"
    } else {
        # Enable required Windows Features for Linux Subsystem
        try {
            Enable-WindowsOptionalFeature -FeatureName $FeatureName -Online -All -LimitAccess -ErrorAction Stop
        }
        catch [System.Exception] {
            Write-Error -Message "An error occured when enabling Microsoft-Windows-Subsystem-Linux feature, see DISM log for more information"
        }
    }
}

# Validate Windows 10 version 1607 build
if ([int](Get-WmiObject -Class Win32_OperatingSystem).BuildNumber -lt 14393) {
    Write-Error -Message "Unsupported build of Windows 10 detected, exiting" ; exit 1
}

# Create AppModelUnlock if it doesn't exist, required for enabling Developer Mode
$RegistryKeyPath = "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock"
if (-not(Test-Path -Path $RegistryKeyPath)) {
    New-Item -Path $RegistryKeyPath -ItemType Directory -Force
}

# Add registry value to enable Developer Mode
New-ItemProperty -Path $RegistryKeyPath -Name AllowDevelopmentWithoutDevLicense -PropertyType DWORD -Value 1 -Force | Out-Null

Check-WindowsFeature Microsoft-Windows-Subsystem-Linux