A. XP doesn't include a voice-recognition component. You can purchase third-party solutions that enable voice command and voice dictation into the OS and other applications (e.g., Microsoft Word).
Popular voice-recognition products include Nuance Communications Dragon NaturallySpeaking (http://www.nuance.com/naturallyspeaking ) and IBM viaVoice (http://www.nuance.com/viavoice ). Most powerful voice-recognition products include an element of training in which the user reads sample paragraphs of text to allow the computer to fine tune the recognition to the user specific accent. If you've previously used voice-recognition software, the new products require far less training and are far more accurate. I wrote this FAQ by dictating to Dragon NaturallySpeaking and had to make only one correction after the 5 minutes of training (even with my British accent).