Enable and Disable Windows Vista Aero Theme
Vista’s Aero Theme has become a very popular part of Windows Vista. This Eye candy may not have come enabled on your new computer, or maybe you just put in a new graphics card so that you can use this theme. Either way, it can be a bit tricky to figure out how to turn this feature of Microsoft’s latest OS (operating system) on.
Drag your mouse to an empty part of your desktop then right click..drag the mouse and click “Personalize”.

Click “Windows Color and Appearance”.
Left click and highlight “Windows Aero” then click “Apply” then “OK”.
And that’s all there is to it! If you should ever have to disable the Aero Theme, just follow the guide above to get to Windows Color and Appearance. Instead of the popup that you got when enabling, you will be at a screen that lets you customize the Windows theme. From there, click the highlighted button in the picture below and choose the theme you want.
And there you have it, how to enable/disable the Aero theme in Windows Vista. From the screen shown above you can also change the colors and opacity of the Windows look.