For most of the last two decades, I have been a Microsoft apologist. I mean, not merely a contented user of the company's operating systems and software, not just a fan, but a champion. I have insisted that MS-DOS wasn't hard to use (once you got used to it), that Windows 3.1 was the greatest innovation in desktop operating systems, that Word was in fact superior to WordPerfect, and that Windows XP was, quite simply, "it."

When I was forced to use Apple's Mac OS (versions 7.6 through 9.2) for a series of jobs, I grumbled, griped, and insisted that Windows was better. Even as I slowly acclimated at work, I bought only Windows PCs for myself and avoided my roommate's recherché new iBook as if it were fugu. I admitted it was pretty, but I just knew that you got more computing power for your buck from an Intel-based Windows machine, and of course there was far more software available for PCs. Yet my adoration wasn't entirely logical; I knew from experience, for example, that Mac crashes were easier to recover from than the infamous Blue Screen of Death. At the heart of it all, I was simply more used to Windows. Even when I finally bought a Mac three years ago, it was solely to meet the computing requirements of some of the publications I worked with. I turned it on only when I had to, sticking to my Windows computer for everyday tasks.

So you might think I would be predisposed to love Vista, Microsoft's newest version of Windows, which was scheduled to be released to consumers at the end of January. And indeed, I leaped at the opportunity to review it. I couldn't wait to finally see and use the long-delayed operating system that I had been reading and writing about for more than three years. Regardless of widespread skepticism, I was confident that Vista would dazzle me, and I looked forward to saying so in print.

Ironically, playing around with Vista for more than a month has done what years of experience and exhortations from Mac-loving friends could not: it has converted me into a Mac fan.

A little context and a caveat: in order to meet print deadlines, I had to review the "RC1" version of Vista Ultimate, which Microsoft released in order to gather feedback from over-eager early adopters. Such post-beta, prerelease testing reveals bugs and deficits that in-house testing misses; debuggers cannot mimic all the various configurations of hardware, software, and peripherals that users will assemble. And Vista RC1 was maddeningly buggy. Although I reminded myself repeatedly that most of the problems I encountered would be fixed in the final version, my opinions about Vista are probably colored by my frustrations.

Still, my very first impression of Vista was positive. Quite simply, it's beautiful. The Aero visual interface provides some cool effects, such as translucent window borders and a way to scroll through a 3-D "stack" of your open windows to find the one you want. Networking computers is virtually automatic, as it was supposed to be but never quite has been with Windows XP. The Photo Gallery is the best built-in organizer I've used to manage digital pictures; it even includes basic photo correction tools.

But many of Vista's "new" features seemed terribly familiar to me--as they will to any user of Apple's OS X Tiger operating system. Live thumbnails that display petite versions of minimized windows, search boxes integrated into every Explorer window, and especially the Sidebar--which contains "Gadgets" such as a weather updater and a headline reader--all mimic OS X features introduced in 2005. The Windows versions are outstanding--they're just not really innovative.

Unfortunately, Vista RC1 contained bugs that rendered some promising features, such as the new version of Windows Media Center, unusable for me (an acquaintance who acquired a final copy of Vista ahead of release assures me that all that has been fixed).

My efforts to get Media Center working highlighted two big problems with Vista. First, it's a memory hog. The hundreds of new features jammed into it have made it a prime example of software bloat, perhaps the quintessence of programmer Niklaus Wirth's law that software gets slower faster than hardware gets faster (for more on the problems with software design that lead to bloat, see "Anything You Can Do, I Can Do Meta"). Although my computer meets the minimum requirements of a "Vista Premium Ready PC," with one gigabyte of RAM, I could run only a few ­simple programs, such as a Web browser and word processor, without running out of memory. I couldn't even watch a movie: Windows Media Player could read the contents of the DVD, but there wasn't enough memory to actually play it. In short, you need a hell of a computer just to run this OS.

Second, users choosing to install the 64-bit version of Vista on computers they already own will have a hard time finding drivers, the software needed to control hardware sub­systems and peripherals such as video cards, modems, or printers. Microsoft's Windows Vista Upgrade Advisor program, which I ran before installing Vista, assured me that my laptop was fully compatible with the 64-bit version. But once I installed it, my speakers would not work. It seems that none of the companies concerned had written a driver for my sound card; it took more than 10 hours of effort to find a workaround. Nor do drivers exist for my modem, printer, or several other things I rely on. For some of the newer components, like the modem, manufacturers will probably have released 64-bit drivers by the time this review appears. But companies have no incentive to write complicated new drivers for older peripherals like my printer. And because rules written into the 64-bit version of Vista limit the installation of some independently written drivers, users will be virtually forced to buy new peripherals if they want to run it.

Struggling to get my computer to do the most basic things reminded me forcefully of similar battles with previous versions of Windows--for instance, the time an MIT electrical engineer had to help me figure out how to get my computer to display anything on my monitor after I upgraded to Windows 98. Playing with OS X Tiger in order to make accurate comparisons for this review, I had a personal epiphany: Windows is complicated. Macs are simple.

This may seem extraordinarily obvious; after all, Apple has built an entire advertising campaign around the concept. But I am obstinate, and I have loved Windows for a long time. Now, however, simplicity is increasingly important to me. I just want things to work, and with my Mac, they do. Though my Mac barely exceeds the processor and memory requirements for OS X Tiger, every bundled program runs perfectly. The five-year-old printer that doesn't work at all with Vista performs beautifully with OS X, not because the manufacturer bothered to write a new Mac driver for my aging standby, but because Apple included a third-party, open-source driver designed to support older printers in Tiger. Instead of facing the planned obsolescence of my printer, I can stick with it as long as I like.

And my deepest-seated reasons for preferring Windows PCs--more computing power for the money and greater software availability--have evaporated in the last year. Apple's decision to use the same Intel chips found in Windows machines has changed everything. Users can now run OS X and Windows on the same computer; with third-party software such as Parallels Desktop, you don't even need to reboot to switch back and forth. The chip swap also makes it possible to compare prices directly. I recently used the Apple and Dell websites to price comparable desktops and laptops; they were $100 apart or less in each case. The difference is that Apple doesn't offer any lower-end processors, so its cheapest computers cost quite a bit more than the least-expensive PCs. As Vista penetrates the market, however, the slower processors are likely to become obsolete--minimizing any cost differences between PCs and Macs.

I may need Windows for a long time to come; many electronic gadgets such as PDAs and MP3 players can only be synched with a computer running Windows, and some software is still not available for Macs. But the long-­predicted migration of software from the desktop to the Internet is finally happening. Organizations now routinely access crucial programs from commercial Web servers, and consumers use Google's services to compose, edit, and store their e-mail, calendars, and even documents and spreadsheets (see "Homo Conexus," July/August 2006). As this shift accelerates, finding software that works with a particular operating system will be less of a concern. People will be able to base decisions about which OS to use strictly on merit, and on personal preference. For me, if the choice is between struggling to configure every feature and being able to boot up and get to work, at long last I choose the Mac.

Erika Jonietz is a Technology Review senior ­editor.

WINDOWS VISTA operating system
$99.95-$399.00
www.microsoft.com/windowsvista