So what's wrong with Microsoft? There is, after all, no shortage of smart software engineers working at the corporate campus in Redmond, Wash. The problem, it seems, is largely that Microsoft's past success and its bundling strategy have become a weakness.

Windows runs on 330 million personal computers worldwide. Three hundred PC manufacturers around the world install Windows on their machines; thousands of devices like printers, scanners and music players plug into Windows computers; and tens of thousands of third-party software applications run on Windows. And a crucial reason Microsoft holds more than 90 percent of the PC operating system market is that the company strains to make sure software and hardware that ran on previous versions of Windows will also work on the new one — compatibility, in computing terms.

As a result, each new version of Windows carries the baggage of its past.