Chromebooks are siphoning market share from Windows PCs

Especially popular are Chromebooks, which are basic Chrome OS laptops for Web computing. Low-price Chromebooks are attractive to students, educational institutions and budget buyers.

Worldwide Chrome PC shipments in 2015 are expected to surpass those in 2014, according to IDC. Chrome PCs accounted for 2.8 percent of all PCs shipped worldwide through the first three quarters in 2015. For all of 2014, Chrome PCs accounted for 1.9 percent of all PCs shipped.

Chrome PC shipments in 2015 will outpace those in 2014, and the growth trend will continue in 2016, said Jay Chou, research manager at IDC.

About 5.7 million Chrome PCs shipped in the first three quarters of 2015, just slightly lower than the 5.86 million shipped for all of 2014. The shipment numbers were derived from yearly worldwide PC shipment statistics provided by IDC.

Total PC shipments worldwide were 276.21 million in 2015, declining by 10.4 percent from 2014, according to IDC. A breakdown for how many of those shipments were for Chromebooks in the last quarter is not yet available.

Expectations weren't high when the first Chromebooks were launched in 2011. Shipments of the laptops started growing at a steady pace when the second-generation of Chromebooks started shipping in late 2013. All top PC makers except for Apple now offer Chrome laptops and desktops.

Google has promoted Chromebook as a low-cost replacement to Windows PCs, especially with more people using Web applications. Google also promised regular OS updates and the ability to use applications offline when the computer isn't connected to the Internet.

Microsoft took on the Chromebook challenge by encouraging PC makers to develop low-cost laptops with the free Windows 8.1 with Bing OS. But that effort ended when Microsoft released Windows 10, Chou said.

PC prices are rising, but Chromebooks remain inexpensive because they use basic hardware. Chrome OS is leaner than

Windows 10 has advantages over the Chrome OS. Windows can be used for a wide range of graphics, productivity and CAD/CAM applications, and it supports more hardware than Chrome OS. However, the Chrome OS is much leaner.

The future of Chrome OS is clouded, though. Late last year, The Wall Street Journal reported that Google planned to merge Chrome OS into Android.