What is Vista Aero?Vista Aero is a beautiful glass-like theme which is embedded in specific version of Windows Vista.Those version includes of Vista Ultimate,Enterprise,Business and Home Premium.
Let's take a tour of Vista Aero.

While the mouse pointer is over an opened task for a moment,it'll appear its thumbnail.(Even works at a playing movie)

The most attractive portion is the Aero Flip 3D.Press"WindowsLogo key + Tab" to activate it.

This is the setting layout for Vista Aero.The glass color can be define as the user like.Noticed the frame of the graph above?That's the appearance of using purple color.
To activate Vista Aero,the system has to rate a grade for the hardware first.
Enter System Properties(Or press"WindowsLogo key + Pause Break"),Click as the below(Windows System Performance Rating).

It will enter the rating window as below:

Click as above(Refresh My Rating Now)to renew the grade.If the hardware pass the requirements,Vista Aero can be now use.(Microsoft declare that Vista Aero only support on genuine version of Windows Vista)