not myself but father uses the winoptimiser suite on second user machines says its amazing at cleaning up unnecessary files and junk from your hard drive, the highest clear up hes had was a two year old machine and it identified 832mb of unnecessary files and clutter. when he returned the machine to its owner he thought it had had a memory upgrade it was so much faster and more stable. surprising how much junk is left to build up as you install and remove apps over a period of time