gartnerA new report from the Gartner research firm paints a dire picture for the traditional PC market, predicting that tablets will quickly become the primary method of computing for most people around the world, exceeding shipments of desktop and notebook computers within two to three years.

ipadminiThe prediction raises the stakes for Microsoft’s attempt to expand into tablets and smartphones. The research firm predicts a decline of 7.6 percent in traditional notebook and desktop computer shipments this year — warning that it’s not a temporary decline but part of a long-term change in user behavior.

Taking into account the entire market for smartphones, tablets and computers, Gartner predicts that Microsoft and Apple will be neck-and-neck in market share in the coming years — with both of them well behind Google’s Android operating system in overall shipments. That’s very different from the traditional view of computing, with Microsoft holding upwards of 90 percent market share in desktop and notebooks, and Apple playing more of a niche role.

“When you look at the numbers together, it’s clear that Microsoft is playing a defensive strategy in trying to keep the PC market but is not taking advantage of the huge opportunity that tablets and phones represent,” said Carolina Milanesi, research vice president at Gartner, via phone this morning.

But from a practical standpoint, can tablets really become our primary computing devices? Milanesi says some people will use both a traditional PC and a tablet, but most will be happy with a tablet as their main computing device, plugging in external monitors and keyboards when needed.

In one scenario, that could give Microsoft the upper hand, if Apple maintains its current strategy, which positions the iPad as a mobile device vs. a full-fledged computer. Microsoft is taking a different approach, expanding Windows further into tablets with the release of Windows 8 and its touch-friendly interface. (Windows 8 can run traditional desktop applications on tablets, although the companion Windows RT operating system for ARM-based processors can’t.)

However, sales of the Surface and other Windows tablets have been tepid so far, and Windows Phone is still trying to gain traction in the smartphone market. Milanesi said Microsoft hasn’t done enough to make its traditional applications, such as Microsoft Office, work well on tablets. She pointed to the rise in popularity of apps such as Evernote as evidence that Microsoft is not moving quickly enough.

Milanesi said widely predicted changes in Windows to support smaller screen sizes would be a step in the right direction, making Windows tablets more effective as portable consumption devices. But the bigger issue, she said, is that consumers have far more choices now for computing, defined broadly.

“That is where the challenge comes in,” she said. “As a default I don’t have just Microsoft anymore.”

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