But you can still use Flip 3D and the taskbar thumbnails
Windows 7: Turn transparent glass on or off
The transparent glass look of Aero Glass in Windows 7 and Vista may look nice, but it can also slow down computers that don't have powerful video adapters. If your computer's performance is being negatively impacted by the Aero Glass feature, you can speed up Windows and still take advantage of Aero features like Flip 3D and Taskbar thumbnails. Glass transparency can be turned off.
This article shows you how to do this in Windows 7 and Vista. The procedure is slightly different in each system.
The following Windows Explorer window shows the Aero Glass transparency effect in Windows 7. You'll notice that you can see the Windows logo on the desktop through the border of the window.
