noises

hello again...
I had this PC built for me about 4 yrs ago and have had nothing but bad luck with it since I have replaced almost everything .... Ok I do have one original hard drive left the other one died about 1 yr ago i think ... now this one is starting to get really noisy at times.. do i quickly burn all my stuff to cd's ? it gets to really winding it sounds like..(when the other drive went I lost it all) do not want that again..........................