Disc Cleanup

I do it every once in a while. You know when it's necessary...when it's freezing, when it's slow, when it makes weird sounds.

The notation reads "The Disc Cleanup utility is cleaning up unnecessary files on your machine", and as it is doing it, it makes this elevating noise, like the sound of an airplane taking off...and then off it goes. Boom. All those dirty, old files gone.

How come human beings don't come with instructions on how to do disc cleanup? It is badly needed.