dear friends, kindly guide me as to how to activate windows xp professional. do i have to pay for it or not?Also let me know is it necessary to activate before installing win xp sp2 because as i understands if an activation is required a message appears reminding you of activation. well i am facing difficulty in installing win xp sp2. further i had downloaded win xp sp1 using win uodate with out any activation issue. i do not know the downloaded sp1 is properly installed and working. how to know it?