Font smoothing (anti-aliasing) options in Windows Vista
This tutorial will introduce the font smoothing options available in Windows Vista, and show you how to set various font-related settings. If your computer is powerful enough to handle Vista's "Aero" theme (such as window transparency), your graphics card will have no problem handling any of the font smoothing options Vista exposes.
While not quite identical, the following terms used are often used interchangeably: "font smoothing", "anti-aliasing" (or "antialiasing"), and "font rasterization". They all refer to the same graphic operation to re-render fonts for higher on-screen readability.
Loading Windows Vista's Personalization Options
To access the personalization options and settings in Windows Vista, right-click on an empty area of your desktop, and choose "Personalize".
This will open the "Appearance and Personalization" page of the Control Panel, which exposes the seven sets of customizable properties for "Window Color and Appearance", "Desktop Background", "Screen Saver", "Sounds", "Mouse Pointers", "Theme", and "Display Settings".
Customizing the font smoothing options in Windows Vista
Click on the "Window Color and Appearance" link to load the following option screen (discussed in detail in the Window Colors and Transparency tutorial). 
Locate the "Open classic appearance properties for more color options" link at the very bottom of this window. This will open the "Appearance Settings" window; click on the Effects button.
The Effects popup dialog will open.
Three anti-aliasing options in Windows Vista
The dropdown menu under the "Use the following method to smooth edges of screen fonts" checkbox includes two choices: "Standard" or "ClearType". Un-checking the checkbox will disable anti-aliasing altogether.
The screenshot above displays the three font smoothing options available in Windows Vista. In the first block ("No font smoothing"), the checkbox has been un-checked, and anti-aliasing is turned off. In the second block, Vista's "Standard font smoothing" technology is used; in the last block, "ClearType font smoothing" was chosen as option. ("ClearType" is a Microsoft implementation of an anti-aliasing algorithm, especially elegant on flat panel monitors.)
Font smoothing is a local option
The font-smoothing-enabling checkbox reads "screen fonts" because Windows Vista's font smoothing settings only affect your computer, and the text seen on screen. Example: composing an email on your computer will show you the email text with your font smoothing settings, but the email recipient will see your email's text with the font smoothing options he or she chose. Likewise, printing a document on paper will not be affected by your font smoothing settings.
Exceptions in font display handling
While most applications will follow the settings you chose for Windows Vista's font display, some handle font smoothing and anti-aliasing differently.
Some programs override the operating system settings for font smoothing: some older programs written in the "Java" programming language, for example, do not support anti-aliasing (the artificial blurring of characters for a more eye-friendly experience). Other applications, like Apple's Safari browser for Windows, handles its own font smoothing, regardless of your Windows Vista settings. Following the Mac OS X approach, Safari uses by default a very "wet" font smoothing algorithm (by Windows standards).
The screenshot above shows the same paragraph on Microsoft's website: left, as viewed from the Safari browser on Windows Vista, and right, viewed from Internet Explorer on the same Vista machine. Again, the cases we mentioned are exceptions, and the vast majority of programs will use your Windows Vista settings for font smoothing.