Around the globe, consumers are ditching their personal computers (PCs). And, believe it or not, that's good news.

Market researcher Gartner Group (NYSE:IT) estimates that most installed PCs are more than three years old, and many of them run older versions of Microsoft's (NASDAQ:MSFT) Windows operating system. Gartner says consumers will be inclined to ditch these aging systems in favor of newer, sexier models from Motley Fool Stock Advisor pick Dell (NASDAQ:DELL), Gateway (NYSE:GTW), Hewlett-Packard (NYSE:HPQ), and IBM (NYSE:IBM).

All told, Gartner expects nearly 100 million PCs to be replaced this year, with global computer shipments to top 186 million, a 13% increase over 2003. The replacement cycle also appears to be accelerating, with 120 million units due to be unplugged in 2005 to make room for new machines. The roughly 220 million replacements this year and next would outpace the total swapped out in 1998 and 1999, during the run-up to Y2K.

Like the first quarter, spring and early summer is expected to be especially hot for PC retailers, according to Gartner. Second-quarter shipments are expected to rise more than 14% from the same period last year. Of course, not every retailer will be affected equally. For example, Dell has been increasing its market share lead over HP, while Apple Computer (NASDAQ:AAPL) has seen its computer systems revenue growth lag worldwide gains.

So, just how good is this news? Good, but let's not get giddy. It's highly unlikely that a renewed appetite for PCs indicates a broader long-term recovery that will bring the computer industry back to its go-go, pre-recession levels. Remember: The PC is nearly 30 years old. That's ancient in tech terms.

It seems more likely to me that Gartner's data confirms what others have long hypothesized: That hawking PCs is no longer a growth business, but a maturing, cyclical industry that more closely resembles auto manufacturing than other tech businesses.

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Fool contributor Tim Beyers knows people who name their PCs. Hey, he loves his Mac, too, but has enough trouble keeping his kids' names straight. Tim owns no interest in any of the companies mentioned, and you can view his Fool profile here.