Market analysts from IDC and Gartner report that PC sales dropped off a cliff in the first quarter, falling 12.5 percent, year over year, to 77.75 million units. To blame: slower-than-expected Windows 8 PC sales and the continued migration to content-consumption devices like smartphones and tablets.

As always, the numbers presented here are an average of those published by IDC and Gartner.

“The Windows 8 launch not only failed to provide a positive boost to the PC market, but appears to have slowed the market," IDC Vice President Bob O'Donnell claims, citing its unfamiliar new UI and costs associated with adding touch to PCs.

Related: "Windows 8 Sales: Hot or Not?"

“Consumers are migrating content consumption from PCs to other connected devices, such as tablets and smartphones,” Gartner analyst Mikako Kitagawa adds. “Even emerging markets, where PC penetration is low, are not expected to be a strong growth area for PC vendors.”

There are a few bright spots for the PC market. Business PC sales actually grew in the quarter (though conversely this means that consumer PC sales are even worse). And Lenovo, alone among PC makers, sold as many PCs in the quarter as it did a year ago. Even Apple, which traditionally bucks PC market trends, sold fewer Macs in the quarter than it did in Q1 2012.

The top five PC makers in the world were HP (15.3 percent market share), Lenovo (15 percent), Dell (11.4 percent), Acer (8.3 percent), and ASUS (6.3 percent). Aside from Lenovo, each posted lower sales than in the year-ago quarter, with two, HP and Acer, posting massive shortfalls of 23.6 and 30.3 percent, respectively. Given current trends, Lenovo could overtake HP to become the world’s biggest maker of PCs as soon as this quarter.

In the US market, the top five players were HP, Dell, Apple, Toshiba, and Lenovo, with Apple posting a .1 percent drop in sales year over year. (IDC reported that Apple’s Mac sales fell 7.5 percent in the quarter, while Gartner claimed a 7.4 percent improvements. Apple doesn’t report US sales, but the firm will report its worldwide quarterly sales later this month. Most do expect the firm to post a drop in Mac sales year over year.)

This quarter’s falloff follows a disastrous launch quarter for Windows 8 in which PC sales fell 5 percent, year over year, to 90 million units. That was the first time PC sales had fallen in the fourth quarter in five years. Analysts had since predicted that market wouldn’t recover until the second half of 2013, but this quarter’s drop was much bigger than anticipated. 

Related: "Windows 8 PC Sales Continue to Lag Behind Those of Windows 7"