Microsoft is defending its decision to turn on its ClearType font rendering technology in Internet Explorer 7 even if users have switched it off system-wide.

ClearType, which debuted with Windows XP, is designed to make text more readable on LCD screens. By default, it's disabled in Windows, but Microsoft's IE 7 team has decided to enable it for the browser, even if the user has not turned on the feature Windows-wide. "The decision to turn ClearType on by default in IE is unusual," acknowledged Bill Hill, a Microsoft researcher, in a posting to the IE team's blog. "But [it] was made because solid research over the past few years has shown conclusively that it improves reading, the task at which IE users spend most of their time."

Hill cited studies that claimed ClearType improved word recognition, reading speed, and reading comprehension, and defended the decision to enable ClearType by saying that users didn't know how to turn it on themselves. "It certainly is unusual that IE is not respecting the system ClearType setting, but the problem is that most users do not know about features that are not turned on by default," Hill said. "We've found that a large percentage of Windows XP users don't know about ClearType, or how to turn it on.

ClearType can be disabled in IE 7 Beta 2 Preview via the Tools/Internet Options/Advanced dialog. To turn ClearType off, uncheck the box "Use ClearType" under the Multimedia section. Unlike Windows XP, the upcoming Windows Vista will enable ClearType by default.