If its colgged with a bunch of music there is no program you will get to make it faster.
Your best bet in this case would be to get another HD internal or external. My question would be is how old is this pc? Do you know what your working with?
There are several factors that can lead to your pc slowing. If you arent willing to get rid of anything (music) (programs that you never use) then you will more than likely continue to have this problem.
Attempting to find a cure for Stupid...