Just wondering if it is worth upgrading my 4200rpm 40 gig hd to a 60-80 gig 7200rpm drive..will i notice a big dif? Prob I am seeing / having is my hd keeps clickling every once in awile when I am loading things..after it clicks the computer does what I asked it too. Does not happen ALL the time but happens more times than I think it should. Any ideas or experience? Thanks!