After years - no - well over a decade and nearer two - of defragging anything that didn't move and seeing no great improvement, yesterday I got a 30 day trial package from Iolo and the defrag amongst other utils has made a very big and surprising difference. My machine is running a lot faster and it was certainly no slouch beforehand.
I did try the "Clear all junk off my machine" wizard though and am left with a C:/ prompt which is why I am now typing this on the other machine. Seriously I am pleasantly surprised. Nope... I don't work for them, hold shares etc. etc. and am not making any endorsement, but the old girl flies as quickly as when new.
Conan