You run the Windows Experience Index (WEI) to measure the capability of the hardware and software configuration on a Windows Vista-based computer. After you do this, the score for 3D business and gaming graphics performance may not accurately represent the actual performance of the gaming graphics. For example, the actual performance of the gaming graphics may be less than you expect, based on the WEI score.

In Windows Vista, the Windows Experience Index rating may display a lower value than expected. You may experience this problem if either of the following conditions is true:

• You start Windows Vista for the first time.
• The Windows Experience Index runs before you update a driver.