I am developing a application that uses kinect speech recognition. I want to recognize the names of the users using Kinect Speech sdk.
Is it possible to recognize all the names(proper nouns) during runtime using kinect Sdk?. Or is there any open source available?
The Kinect does not "recognize speech". It is a microphone array and does little more then just listen. You need to look at Microsoft Speech Platform, or another speech processor in order to process the speech. Reading up on the Microsoft Speech Platform capabilities will help you understand the scope of what you are looking to do.
There are multiple examples of how to work with speech and the Kinect in the Kinect for Windows Developer Toolkit, as well as the code sampless available at the Kinect For Windows Samples CodePlex project. The "Speech Basics" samples comes immediately to mind as someplace you should start.