The Aero Glass Theme

Perhaps the most talked about of Windows Vista's new features is the Aero theme with its Glass color scheme. Part of the discussion has centered on Microsoft's controversial decision to run Aero Glass only on systems with relatively powerful graphics capabilities. It's not so much an issue with home machines because the hardware required to run Aero Glass is becoming more mainstream, thanks to the influence of gaming and media applications.

However, the corporate sector has been doing most of the griping, and that's because in most corporate IT departments, graphics are barely considered during purchasing decisions. The thinking seems to be that if the graphics hardware is good enough to run PowerPoint, it's good enough for a corporate desktop. The entire discussion might be moot, however, because when corporate IT departments finally get around to adopting Vista en masse in 2 or 3 years, Aero Glass-capable graphics should be standard on the kind of midrange PCs that corporate purchasers favor.


Windows Vista performs a hardware check on your system to see if it can handle the Aero Glass interface. If not, Vista shuts off Aero Glass. However, you can use a trick to force Aero Glass on, as long as you're using a WDDM-compliant video driver. In the Registry Editor (Start, Run, type regedit, and click OK), navigate to the following key:


Add a new subkey named DWM and then create a DWORD setting named EnableMachineCheck. Leave the value of this setting at 0, which disables Vista's DWM-related hardware checking. Some caveats concerning this hack:

  • It does not work on all systems.
  • Even if it does work, it can make your system run extremely slowly. (There's probably a reason Windows shut off Aero Glass.)
  • Microsoft might not support the EnableMachineCheck setting in the final version of Vista.

The rest of the Aero Glass talk has centered on what this new theme brings to the Vista interface. The most obvious change is one that you've already had a brief taste of in your brief tour of the Vista interface: the transparency effects that you see in the taskbar and the Start menu.

Transparency extends to all the windows and dialog boxes Vista displays. It even extends to the windows and dialog boxes of applications that weren't built with Aero Glass in mind because the DWM displays all screen output, so it can apply the transparency effectindeed, any of the Aero Glass effectsto any window or dialog box.

Figure below shows Vista with a window and a dialog box displayed.

You can see (hopefullythe effects could be difficult to discern in black and white) that the transparency effect is most apparent in the title bar, but it also applies to the window and dialog box borders. What's the point, you may ask? I think Microsoft's goal here is both simple and subversive: to change the user's focus from the window to what's inside the window.

In other words, by reducing the visual presence of the window title bar and borders, Vista shifts the focus from the container to the content. Many of the features that you learn about in Chapter 4including desktop search, virtual folders, document metadata, and a de-emphasis on the traditional disk-and-folder storage modelare also designed to bring content to the fore.

Aero Glass also applies the following effects to the Vista interface:

  • Each open window and dialog box has a drop-shadow effect.
  • When you hover the mouse pointer over a window button, the button "lights up": You see a blue glow for the Minimize and Maximize buttons, and a red glow for the Close button.
  • Almost anything that's live (in the sense that clicking it will trigger some action) gets highlighted when you hover your mouse pointer over it.
  • In a dialog box, the default button (usually the OK button) uses a repeating fade effect in which the color that normally appears when you hover the mouse over a command button appears to fade in and out.

These interface changes are, thankfully, subtle. With access to Direct3D and graphics hardware accelerations, Microsoft could have cranked up the eye candy and turned Vista into a version of Halo or some other frenetic game. Instead, they opted for muted effects that enhance the look of the interface while also making users' lives easier. (For example, it's going to be much harder in Vista to accidentally click Close when you meant to click Maximize because that glowing red Close button will put an instant "Stop!" message into your brain.)

Another useful Aero innovation is the use of animations to enhance interface actions. For example, when you minimize a window, it noticeably shrinks down to its taskbar icon. When you restore it, the window expands to its previous size and position. Similarly, when you close a window, it fades from view. Aero Glass also implements blur effects when an action is performed quickly.