Thanks for the thoughts and info!
I've copied anything I feel I can't lose (like photos) and things I don't want to lose (like patterns) so I'm feeling better about it if it does die on me.
We are now thinking that some of the noise coming from the CPU might be vibration although the HD or something is way too noisy on it's own, too. Based on the prices of new computers and the age of this one we are going to try to hold out till after Christmas and just buy a new one. If this one bites the dust earlier then I guess we'll just have to deal with it, but hopefully it'll hold out. Maybe I'll just get some earplugs..