Install the (x86) Microsoft Speech Platform Runtime v11.0

Get it directly from Microsoft: http://www.microsoft.com/en-us/download/details.aspx?id=27225
Be sure to choose the x86 version (see image to the right)

Download recognition and TTS languages you want here

Even if you're looking for non-English languages, ignore the fact that it says "English" and just click the big red "Download" button
Place checkmarks next to all the files you want
Click Next

Note that:

Speech recognition engines for various languages are at the top and the filenames start with MSSpeech_SR_
TTS voices are at the bottom and the filenames start with MSSpeech_TTS_

"All files" means at least: (1) the SpeechPlatformRuntime.msi and (2) a speech recognition (MSSpeech_SR_) file, but may also include more speech recognizers as well as TTS engines if you wish to install more.
Even if you intend to only use the program in English, you need to download one of the English engines. The "lightweight" speech recognizer that is included with the runtime does not work (as per the video tutorial below).
Follow the simple installation instructions as they are presented to you.
I don't think a restart is required.

Run VoxCommandoSP.exe
Go to "Options" to select speech engine
Continue using your old TTS voices using the TTS plugin
Use the "TTSMS" plugin for Microsoft voices (Free to download. They are not great, but are available in many languages.)

Here is a video walkthrough discussing the new features and the installation of MS Speech Platform