With Windows XP, ClearType delivers improved font display quality over traditional forms of font smoothing or anti-aliasing. ClearType improves readability on color LCD displays with a digital interface, such as those in laptops and high-quality flat panel displays. Readability on CRT screens can also be somewhat improved.
Use this online tuner to turn on and tune your Windows XP ClearType settings. Alternately, download a Windows XP PowerToy version of the tuner.
Turn on Windows XP ClearType