Analysts from both Gartner and IDC agree that PC sales declined in the fourth quarter of 2012, the first time this has happened in five years. That the decline came during the launch quarter for Microsoft’s much-hyped Windows 8 is of course bad news, and suggests that the PC industry will need to step up with better devices in the year ahead to prevent a complete implosion in this market.

Hardware makers delivered 90 million PCs in Q4 2012, using an averaged estimate from the two analyst firms. That’s down over 5 percent from the 95.5 million units these firms shipped in the same quarter one year ago.

IDC says it wasn't surprised by the lackluster sales, despite the fact that Q4 and full year 2012 PC sales were well below its own estimates. “Consumers as well as PC vendors and distribution channels continued to be diverted from PC sales by ongoing demand for tablets and smartphones,” IDC noted. “In addition, questions about the use of touch on Windows PCs versus tablets slowed commercial spending on PCs.”

Gartner said that it was no longer possible to blame the economy on weak PC sales, and that PC usage was simply changing along with the technology. “Tablets have cause PC users to shift consumption to tablets rather than replacing older PCs,” Gartner principal analyst Mikako Kitagawa notes. “We increasingly suspect that most individuals will shift consumption activity to a personal tablet, and perform creative and administrative tasks on a shared PC.” Worse, that shared PC will be replaced more slowly or not at all.

For Microsoft, the news comes as a terrible blow in the wake of its claims of success for Windows 8, with the software giant announcing last week that it had sold more than 60 million licenses to the new OS since its launch two months before. But while these sales are increasingly suspect, with many of them being to PC makers for devices that have not yet been sold to customers, here’s an uncomfortable truth: Both Gartner and IDC count channel sales too. So their dour reports about Q4 do not exclude the Windows 8 license sales Microsoft made during this time period.

More to the point, if there is one thing both IDC and Gartner agree on, it’s that Windows 8 has done nothing to help jumpstart PC sales. That said, while both firms hold out hope that a second generation of more compelling Windows 8 devices now coming to market could help, the firms oddly disagreed on whether Windows 8’s touch features were a boon or bust.

“The launch of Microsoft’s Windows 8 did not have a significant impact on PC shipments in the fourth quarter,” Gartner said. “Some PC vendors offered somewhat lackluster form factors in their Windows 8 offerings and missed the excitement of touch.”

“As Windows 8 matures, and other corresponding variables such as Ultrabook pricing continue to drop, hopefully the PC market can see a reset in both messaging and demand in 2013,” IDC claimed, noting that PC makers pushed Windows 8 touch features too much in Q4. Perhaps they should focus on other features, like Windows 8’s “more secure, reliable, and efficient user experience” instead, the firm suggested.

The quarter also marked some interesting changes in the makeup of the PC maker leaders. HP retained its top spot overall, but ThinkPad maker Lenovo closed the gap significantly and could now overtake HP as the number-one PC maker sometime in 2013. HP sold 14.8 million PCs worldwide in Q4 2012, good for just under 16.5 percent market share, and down a bit year over year. But Lenovo PC sales surged 8.2 percent year over year, with the firm selling 14 million PCs in the quarter, with 15.6 percent market share. Dell, Acer, and ASUS round out the top five, with both Dell (-21 percent) and Acer (-20 percent) experiencing huge overall unit sales declines. Indeed, of the top five PC makers, only Lenovo experienced growth.

(The picture in the United States, as always, was a bit different. There, the top five PC makers are HP, Dell, Apple, Lenovo, and Toshiba. HP and Lenovo experienced double-digit growth in the United States, while Dell and Acer experienced double-digit declines. Apple Mac sales were flat or slightly up.)

For all of calendar year 2012, the picture is likewise less than rosy. Hardware makers sold 353 million PCs in all of 2012, again using an averaged estimate from Gartner and IDC. This was significantly below projections; at one point, IDC claimed PC makers could sell as many as 400 million PCs in this time period, and Microsoft used this figure many times to describe the developer opportunity for Windows 8.

Lenovo again comes out as the big winner for calendar year 2012, with almost 17 percent growth year over year. The firm sold 52.3 million PCs in 2012, good for second place behind HP, which registered 57 million units sold in the same time period, a decline of 6.7 percent year over year. Of the remaining top five PC makers, Dell and Acer both experienced declines in 2012 while fifth-place ASUS surged 17 percent to 24.1 million units.