Lose What You Don't Need- Make sure you've completely uninstalled previous versions of Windows.
Hose Out the Background- Check out tray icons and kill anything that's running if you aren't using it.
Get rid of startup items- In start, type MSCONFIG and then it will show you all the programs that start with Windows. This takes up memory. Uncheck anything you don't use regularly.
Eliminate many interface options- ie. disable the sidebar, disable transparency, and choose the Non-Aero theme, which will enhance performance.