Do I get additional speech recognition engines after installing Windows 7 language packs?

I am developing a speech recognition application on Windows 7. I have a Windows 7 Home Premium with en-US as language. It ships with an English speech recognizer engine.

I would like to be able to switch between spoken languages on my application. After some research I've found that on Windows 7 Ultimate you can install 35 additional "language packs" via Windows Update and I'm thinking on buying Windows 7 Ultimate.

My question is:

Will installing any language pack from Windows Update also install additional speech recognition engines?

If not possible, how can I make my speech application to become automatically Spanish, French and German "fluent"?

Yes, you will gain additional speech recognition engines after installing a language pack.
I installed a German Windows 7 and later I installed English language pack from Windows Update.

Proof screen

See my Advanced speech options tab while being on Windows 7 Ultimate x64

Do you need a dictation grammar? does your application transcribe anything the user speaks or does it only react to a fixed vocabulary? If you do not need transcription, you can use the free Microsoft Server speech engines (even on Home Premium). One advantage the desktop speech recognition engine has over the server engines is the dictation grammar. If you can use a fixed vocabulary, you may not need to upgrade.

http://stackoverflow.com/questions/2977338/what-is-the-difference-between-system-speech-recognition-and-microsoft-speech-rec may be helpful to explain.