Microsoft Vista: Should you buy now?

After five years in development, Microsoft's new operating system is finally about to hit the street. Is it a keeper? Fortune's Peter Lewis takes it for a test drive.

By Peter Lewis, Fortune senior editor

(Fortune Magazine) -- What does Windows Vista have in common with the just-christened nuclear aircraft carrier George H.W. Bush? Answer: They are both powerful flagships of technology that took five years and billions of dollars to build.

Also, while they'll both be in use for years to come, they're almost certainly the last of their respective kinds. The world now moves at Internet speed, and slow, complex behemoths - whether warships or software - are being forced to become smaller, faster and more maneuverable.

Vista is anything but. After numerous well-publicized delays - two years of core coding had to be scrapped and rewritten to plug security holes - Vista will be launched on Jan. 30, backed by Microsoft's largest-ever marketing blitz.

Vista is actually an armada of different versions: Windows Vista Home Basic ($199 for the full version, $100 for the upgrade), Windows Vista Business ($299/$199), Windows Vista Home Premium ($239/$159), Windows Vista Ultimate ($399/$259), and Windows Vista Enterprise Edition (prices vary). One of those versions almost certainly will be loaded on your next new Windows-compatible PC.

How does Vista stack up? After a couple of months of testing in the Fortune gadget laboratory, my verdict is this: Vista is definitely the best operating system Microsoft (Charts) has ever made. (Mac users, stop snorting!) It offers greater security and reliability than previous versions of Windows; a prettier, more useful user interface; better support for networked computers; backward compatibility with older programs, plus a better bridge to future technologies like 64-bit computing; and greatly improved search abilities.

I'll definitely upgrade from Windows XP - but probably not until Microsoft releases the inevitable bug-fixing and hole-patching Vista Service Pack, which may be months from now.

Vista's negative ledger is shorter - some significant headaches but no deal breakers. One big hurdle is that you'll need serious hardware to take advantage of the best features. Only the most expensive versions of Vista - Home Premium and Ultimate - offer the new "breakthrough Vista experience" Microsoft is touting, including the glassy Aero interface and fancier graphics. Older PCs lack the horsepower to run it. If you haven't bought a new PC in the past year or so, you'll probably have to grab your wallet and a screwdriver to upgrade your hardware. That's not including the hundreds of bucks you'll spend for new Vista-enabled versions of your favorite applications.

Even if you have a Vista-ready computer, upgrading to Vista is vexing. For starters, new PCs labeled "Vista ready" may not be capable of running the premium versions, which are, of course, the versions you'll want. To run them, you'll need a "Vista Premium ready" PC. (To find out which version of Vista your PC can handle, visit www.windowsvista.com/upgradeadvisor.)

If you're still eager to upgrade, the best way to go is a so-called clean install - backing up and wiping clean the hard drive, then reinstalling everything - a hassle even for experienced users. And then there's the issue of drivers, the software that Windows PCs need to work smoothly with printers, scanners and other peripherals. I wasted a full day tracking down and troubleshooting updates just so I could print a letter.

Any major operating system upgrade is a hassle, especially for corporate information-technology managers who oversee thousands of PCs. That's why only a small share of corporate users will be upgrading to Vista this year. Most who do will replace older PCs with new ones preloaded with Vista.

"For most organizations it's going to take 12 to 18 months of testing," says Michael Silver, senior software analyst for technology consultants Gartner Group. "Testing applications, waiting for software vendors to come up with new [Vista-specific] versions - by that time the machines in the office are going to be another 18 months older. Why spend the money to upgrade if you're only going to have it for another six months to a year?"