For all those who have been using windows7 here is the way for activating speech recognition future which is provided along with the operating system. All you need to have is just a microphone. Though this feature is not so advanced and can recognize your accent but it is a useful feature to at least play some time around with it. Unlikely to SIRI which recognizes whatever you say windows7 is...
How to control windows using voice commands? ( Speech Recognition )
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