My McAfee anti-viral, anti-hack, anti-this, anti-that software service updated itself a little while back. Aside from an irritating attempt to assume control over some security functions that I use other tools for, it dropped in a pretty large set of generally reasonable functions to protect my system. Let me qualify that. That’s “generally reasonable” for Windows. For just about any other modern operating system, they’d be redundant or meaningless.

The problem is that even after disabling a lot of the new functionality, this update also did a fine job of reducing the overall performance of my machine by about 30 percent. The incredible load imposed by this class of “defensive software” is a direct result of major architectural flaws in Microsoft Windows.

Yet it seems that rather than make fundamental changes to the OS (which would also require all providers of drivers and systems software to do major work), Windows Vista simply implements the same sort of performance-killing layer of protective sludge.

Apple has already managed to jump on this in one of their “Nerdy PC guy versus Cool Mac Dude” ads. In fact it’s kind of nice to see Apple picking on Windows without resorting to excessive distortions (Sure, I’m going to be more creative just because I buy a Mac? Give me a break).

In my case, I’ve addressed the performance problem by disabling most of the functionality in my security software, and I know I’m not alone. It’s a calculated risk based on some simple math: if I spend ten minutes a day being delayed by my security systems, it’s not long before that adds up to more time than it takes to recover a damaged machine.

But it’s led me to look at the whole operating system issue one more time. The number of packages that I use that require Windows continues to decrease, but there’s a few that I’d need to keep around. I can easily do more than 90% of my work in a Linux/KDE environment, and there’s nothing to stop me from reorganizing my system into a dual boot configuration so that I could get to Windows when I needed to. In fact, for a couple of hundred US Dollars, I could install VMWare and swap between desktops fairly seamlessly.

There’s a dual threat to Windows. Open source desktops are becoming more and more capable over time. The range and calibre of applications that run in these environments continues to improve to the point where almost everything that’s required on a day to day basis is readily available. Apple’s OS X is in the same position, with lots of nice consumer-friendly applications available to sweeten the proposition, and now that Apple is using Intel hardware, their “cult members only” pricing has moved down a notch to merely “over the top”.

As Microsoft continues to enclose Windows in layer after layer of retrofitted defensive software and restrictive but futile Digital Rights Management systems, one wonders how long it’s going to be before the Windows value proposition — which is increasingly predicated on the use of existing installed applications — becomes unsustainable.

For a lot of companies, the business case for migration to a Linux desktop has to be getting close to compelling. For consumers, the attraction of moving to a Mac OS X platform has to be gaining ground. If Apple gets confident enough to make OS X available on hardware from other suppliers like Dell and HP, things could get very rough, very quickly. This is starting to look like the beginning of a perfect storm for the boys in Redmond, and it’s doubtful whether they have the will — or the wherewithal — to change course.

All this is suddenly starting to make Apple Inc. stock look like a pretty good deal.