Today's U.S. employment data has left investors disappointed, and stocks opened lower this morning. The S&P 500 (SNPINDEX:^GSPC) and the narrower, price-weighted Dow Jones Industrial Average (DJINDICES:^DJI) are down 1.15% and 1%, respectively, as of 10:10 a.m. EDT.

The shift to mobile takes its toll on Microsoft
In a report released yesterday, research firm Gartner predicts that consumers will purchase more Apple (NASDAQ:AAPL) devices than PCs, tablets, and smartphones running Microsoft's (NASDAQ:MSFT) Windows operating system.

For Apple, that would be another milestone in the company's extraordinary rise from niche player to technology standard-setter. For Microsoft, the issue is not simply being overtaken, but the chasm between the growth rates of the two platforms. Last year, Apple's consumer sales of iPhones, iPads, and Macs totaled 159 million against 175 million Windows devices; this year, Gartner expects the total for Apple to surge to 233 million (+46%) while Windows device sales inch ahead to 181 million (+3%).

It's not all bad news for Microsoft, as Gartner believes its position in the corporate PC market will support the Windows franchise for years. However, "as consumers shift their time away from their PC to tablets and smartphones, they will no longer see their PC as a device that they need to replace on a regular basis," says Gartner's Carolina Milanesi. Furthermore, I believe there is a risk that consumer preferences will increasingly dictate business IT standards if workers demand to use the same devices at work that they use at home.

For all its human and financial capital, Microsoft appears so far unable to master the shift toward mobile computing. These latest estimates illustrate the magnitude of the challenge for a company that may be disappearing before our very eyes.

Fool contributor Alex Dumortier, CFA has no position in any stocks mentioned; you can follow him on LinkedIn. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.