WEI isn't the best indicator for computer performance, especially for laptops. My netbook only scores a 2.0 (Aero Graphics) and Windows 7 absolutely flies on it, especially after upgrading the RAM to 2 GB. Even with a 2.0, Aero still works as well.
Bottom line is, unless you're noticing a considerable drop in performance from where you feel your laptop should be at, don't worry too much about the WEI score.