Microsoft operating systems have been a "variable quantity" ever since I started working with them back in the Cretaceous Era. DOS 3 was good; DOS 4 was a clunker. The same variability held true with Windows: Windows 98 was good, Windows ME was a clunker. Then Microsoft put together back-to-back winners with Windows 2000 and XP, and some industry observers thought that the operating system rollercoaster ride might have smoothed out at last.
But it was not to be. I can't quite bring myself to call Windows Vista a dud, because many aspects of its design (such as the revised administrative tools) show a welcome maturity and thoughtfulness; but the product did not receive much love in the marketplace. If you are Microsoft, you know that you've got a problem when even Intel does not adopt your flagship OS for internal use. Microsoft's attempts to shine up Vista's image through the "Mojave Experiment" TV commercials may have changed a few consumer minds, but corporate IT planners in droves decided to stick with good old Windows XP, notwithstanding the fact that Microsoft ended mainstream support for that OS on April 14, 2009. (This means that all XP support now costs money, except for security updates, which will continue through 2014.)
Based on my experience with the beta code, Windows 7 just might change their minds. It incorporates many of the best features of Vista while fixing many of its worst features. It's a bit of a stretch for Microsoft to give it a new name: it's really closer to "Vista R2" than anything else, in that it's more than a service pack but less than a new product. (Microsoft execs say that it uses the "same core architecture;" Gartner Group calls Windows 7 a "polishing" release.) But we won't quibble about the name too much. This product looks and feels better than anything Microsoft has released in years.
This white paper introduces the key areas in which Windows 7 differs from Vista - areas you'll need to focus on if you're thinking of moving to Windows 7, either from Vista or from XP. Use it as a starting point for your own evaluation research.