Ten or more replies and not one addresses the solution. First is shut down and restart the computer. Then run disc cleanup (it is accessories, system tools). I use AVG Free for my virus protection. Costs nothing, does a great job and does not eat up resources like Norton or Mc Afee. If it is not done automatically run Didc Defragmenter also. All of these things will help speed up your machine unless something like a bad virus is eating away your memory. One other thing that can be done is to uninstall unused programs. But you have to have a general idea of what programs are in your machine that you do not need.

Good luck.