PC shipments decline worldwide as market readies for Windows 10

Overall, manufacturers shipped 66.1 million units worldwide, including desktops and laptops running Microsoft's Windows and other operating systems. That was slightly less than expected. IDC said in its report that the declines were caused in part because PC sales during the same period in 2014 were boosted by people purchasing new computers to upgrade from Windows XP, which Microsoft stopped supporting in April of that year.

In addition, manufacturers' channel partners reduced inventory in the second quarter in preparation for new devices running Windows 10, which led to shipment declines. Customers outside the U.S. were also affected by shifting exchange rates that at times raised the prices for computers overseas as some foreign currencies weakened relative to the dollar.

The worse than expected quarter wasn't much of a cause for concern for Loren Loverde, IDC's vice president of worldwide PC trackers and forecasting. He said that the decline "fits with expectations," and that the PC market will stabilize in future years.

"We continue to expect low to mid-single digit declines in volume during the second half of the year with volume stabilizing in future years," Loverde said in a press release.

Loverde said that manufacturers may not see much of a bump either from the launch of Windows 10 later this month. Because Microsoft is offering anyone with a PC running Windows 7 or 8.1 a free upgrade to its new operating system, consumers who would have otherwise purchased a new device in order to upgrade may hold off on doing so and instead opt to upgrade their existing machine, at least for now.

Lenovo held the top position in worldwide PC market share, with slightly more than 13.4 million units shipped. That translates into 1 percent growth over the previous quarter, and a 7.5 percent decline year over year. Apple was the only company to grow its worldwide shipments over the second quarter of 2014, shipping 5.1 million Macs in the second quarter of 2015. One of the Cupertino-based company's biggest advantages in the current computer market is its ability to stay out of the price competition that has been hurting makers of Windows PCs.

Gartner's report on computer sales reached a similar conclusion, with its analysts saying that shipments declined 9.5 percent year-over-year. The difference between the two reports likely stems in part from IDC excluding 2-in-1 devices like Microsoft's Surface Pro 3 (what the firm calls "tablets with detachable keyboards") from its research. Gartner includes those devices, which make up a growing percentage of the Windows device market.