Make Windows Mobile Text-to-Speech voices available for System.Speech.Synthesis

Okay, thanks to reddit comment from a 'Pessimist__Prime' (details below) I found a way to enable some more voices on my (Win 8+) machine, without installing anything else.

Under text-to-speech settings I could see various voices (such as "Microsoft James Mobile") but these voices were not visible when calling synth.GetInstalledVoices (where synth = new System.Speech.Synthesis.SpeechSynthesizer()).

However, by copying some details from:

HKLM:\software\Microsoft\Speech_OneCore\Voices\Tokens

to both these locations:

HKLM:\SOFTWARE\Microsoft\Speech\Voices\Tokens
HKLM:\SOFTWARE\WOW6432Node\Microsoft\SPEECH\Voices\Tokens

...all of the installed voices became available.

Here's the script for performing the copy, provided by Pessimist__Prime at reddit:

$sourcePath = 'HKLM:\software\Microsoft\Speech_OneCore\Voices\Tokens'           # Where OneCore voices live
$destinationPath = 'HKLM:\SOFTWARE\Microsoft\Speech\Voices\Tokens'              # For 64-bit apps
$destinationPath2 = 'HKLM:\SOFTWARE\WOW6432Node\Microsoft\SPEECH\Voices\Tokens' # For 32-bit apps
cd $destinationPath
$listVoices = Get-ChildItem $sourcePath
foreach($voice in $listVoices)
{
    $source = $voice.PSPath #Get the path of this voices key
    copy -Path $source -Destination $destinationPath -Recurse
    copy -Path $source -Destination $destinationPath2 -Recurse
}

Source