Hmm...santoshtrivedi...so you want to become a l33t h4x0r type d00d?Well,here's a rule then...Try to find answers to your doubts before you come and ask them.You want to know your computer?Take it apart(both hardware AND the OS),go google up every doubt you may have..and THEN if you still dont understand,feel free to come here and ask.Oh,and that is EXACTLY the way to respond to someone who hasn't gone and tried to find something for himself.Also,you're new...changing that attitude may help

Cheers.