As Microsoft has seen with Windows XP, it's not just users' operating system dependencies that can keep them from upgrading; it's their browser dependencies, too.
The same way that IE6 was the browser that Microsoft built into Windows XP -- and around which many business customers standardized -- IE8 is the browser variant that Microsoft integrated into Windows 7, which is the newer version of Windows favored by many business users.
Similar to the case with Windows XP, many businesses have built and certified line-of-business apps specifically for the Windows 7/IE8 combination.
