Long Zheng wrote in his i started someting blog :
Some of you may, and some of you may not, (so that’s everybody) know Windows Vista has 4 tiers of user interface experience, from the best to worst: Aero Glass, Vista Standard, Vista Basic and Windows Classic. So why so many? Who knows, graphics designers unemployment at an all time low in Redmond? But regardless of whether you like it or not, these are the choices that will be shipping with Vista so let’s understand it while we can.
I have taken the liberty (because no one else is as bored as I am) of taking 28 screenshots to compare the 4 different interfaces.