We wanted to make Windows 7 the most accessible operating system that Microsoft has ever produced. It became clear as we planned this release, however, that the notion of Accessibility is not as simple as it may appear. It is tempting to think about Accessibility like Security: either you have a known failure, or your system is believed to be secure/accessible. This definition turns out to be limited, though. How do you deal with the fact that the needs of customers who are blind are very different from the needs of customers who are deaf? The needs of customers who are blind are even different from those of customers with reduced vision: a magnification tool is useless for one group and crucial for the other. And what do we make of cases where something is technically accessible but practically frustrating, like a common user scenario that takes 36 keystrokes to execute? Clearly, Accessibility wasn’t going to boil down to a simple yes/no question. It is really more like a particular kind of usability, but usability for a specific set of audiences with individual needs.