I don't understand your problem...
But if you can't find where to install it from, go to control panel > regional & lang settings (or something like that) > keyboard & languages (probably 3th bar) > Install/Uninstall languages. That's it.
I'm not sure english names of options, beacuse i'm not using english Win7.
Btw, if you are trying to run mir server on Win7 64bit, let us know the results.