Realistically, though, with the worldwide installed base of all versions of Windows at around 850 million, according to Gartner Dataquest, the challenge of making Windows truly secure for the first time is significant. Millions of people for years and years have been logging into Windows with carte blanche rights to change anything in the operating system that can be changed -- a large security vulnerability. Crafting the system to prevent that behavior is nontrivial. So I'm giving Microsoft a pass for having spent a lot of its development efforts on security for this release of Windows, but I'm far less forgiving about the user experience trade-offs that some of those Microsoft security efforts require.

Beyond security, Vista's single best feature is the graphics subsystem and Aero "Glass" user experience it enables (when your hardware supports it). Direct support for advanced 3-D graphics processors, vector-based graphics and fonts, DPI scaling, reflections, transparencies, 3-D movements and a whole range of visual improvements account for the most profound change to Vista. The new integrated desktop search features, the ability to save searches as dynamic collections, and some new data sorting and visualizing options (including "stacking") make up the next most significant feature set.

Another what's-new story about Vista concerns bundled applications. Vista adds several new apps, such as Windows Defender, Sidebar, Calendar, Photo Gallery, DVD Maker, Fax and Scan, and BitLocker full-volume encryption. Significantly upgraded bundled apps include Internet Explorer 7+, Windows Mail (Outlook Express), Media Player 11, Movie Maker, Speech Recognition, Windows Meeting Space (Wi-Fi-based peer presentation/file sharing), automatic hard-drive defragmentation and disk backup.

Additionally, Windows Media Center and Tablet PC Edition are available in several versions of Windows Vista -- more like a feature set than a different version of the operating system. Vista offers both 64- and 32-bit support. Microsoft has also developed a new hybrid "sleep" mode for both desktop and mobile PCs that for the first time makes rapid shutdowns and restarts very easy. While sleeping, mobile computers use very little battery charge. Even when fully powered down, Vista shutdown and start-up times are noticeably faster than those of Windows XP.

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