Have you ever wished that the zoom slider on your Microsoft Natural Ergonomic 4000 Keyboard could be used to scroll instead scroll? I surely found the zoom button placed right in the middle of my keyboard to be a major waste of prime real estate and set out to re-purpose it for scrolling.
First, make sure that you install the lastest version of the Microsoft software (found here). Not only will this installation allow you to make the adjustment being discussed, but it will also allow you to customize the actions for the rest of the shortcut keys. For example, I reassigned the email button to open a webpage right to gmail.com instead of having it open Outlook (default behavior).