Answer:First, your hardware must meet the requirements of the Windows^® Vista™ Premium system. If not, you may not enable Windows^® Aero.
Windows^® Vista™ Premium system - Hardware Minimum Requirements

Item	Requirements
CPU	x86-compatible 32-bit CPU or x64-compatible 64-bit CPU
Memory	512MB Single Channel (Premium, Discrete models) 512MB x 2 Dual Channel (Premium, embedded models)
VGA	DirectX9.0 (with WDDM Driver) with 128bit VGA memory (Premium)
Audio	UAA Audio (HD Audio, USB Audio and IEEE1394 Audio) (Premium or Basic depends on Codec Vista logo level)

Second, please kindly refer to below steps to enable Windows^® Aero feature:
1.Press right button of mouse at Desktop and click "Personalize".


2.Enter into "Windows^® Color and Appearance" setting


3.Refer to below image to enter "Open classic appearance properties for more color options" setting.


4.Set "Color scheme" as "Windows^® Aero".