1) Remove unwanted items from startup.2) Clean up all your system restore points(it takes a lot of space)3) Defrag your drive4) Use CCleaner to clean out all the crap stuff from your PC. It also cleans up the registry from unwanted items too.5) When uninstalling a software, use Revo Uninstaller. It will thoroughly uninstall and will leave no entries related to that software in your PC.Also, speed depends upon how much RAM you have. If you are not interested in buying a new RAM, try eboostr, IF you have a Pen Drive.