If you buy a brand new PC with Windows Vista, you might find a big surprise when Vista does not look the same as the Vista in the showroom. After installing Vista, the so-called Windows Experience Index is calculated for your PC. Depending of the results of this test, certain features of Vista are enabled or disabled to give you the optimal performance.
This is great from a technical point of view, but makes it difficult to know exactly what you are buying. Only at home you will find your Experience index and see what has been disabled. And until now I haven’t seen any hardware manufacturer publish the Windows Experience Index for the PC’s they sell.