Speech recognition

Hello, I'm making my OS and I need how to get System.Speech.dll work. I have a code to recognize voice, but when I run the debug, Visual Studio gives me an error saying that there's not any speech recognition program installed! What should I do? Thanks. 

it may depend on your OS version. Keep in mind that speech recog only works from Windows 7 Ultimate to later OSes. And only in a few languages.
support.microsoft.com/en-us/help/14213/windows-how-to-use-speech-recognition