High cpu usage without user initiated processes would mean you've likely got a ton of startup items. Click on the Start orb, type msconfig, hit Enter. In the msconfig window, click on startup tab and uncheck anything you dont need to start automatically. E.g. on my computers, only the AV, touchpad driver and password manager are checked.
Is this a clean install of win7 or an upgrade from vista, xp etc? Driver/software conflicts can also drive the cpu crazy.
Other than that, heat is a bit of a nuisance in notebooks. If you are handy with it, you can try changing out the thermal paste- that would likely help the most or maybe get a service center to do it for you. You can also buy a notebook cooling pad- that'll draw the warm air out and improve ventilation.