Consumers now see tablets as direct substitutes for the traditional PC. Consumers now see tablets as direct substitutes for the traditional PC.

The fourth quarter saw another slide in PC shipments, with volumes dropping 4.3% to only 90.3 million units, according to Gartner.

The slump is being seen as a defeat for Windows 8, previously hailed as the last champion of the personal computer, as consumers are showing a clear preference for mobile devices, rather than supplementing a traditional PC with a tablet.

The shift comes even as Microsoft OEM partners released a range of hybrid devices, ostensibly supplying consumers with a device that could be classified as both a PC or a tablet.

"Tablets have dramatically changed the device landscape for PCs, not so much by 'cannibalizing' PC sales, but by causing PC users to shift consumption to tablets rather than replacing older PCs," said Mikako Kitagawa, principal analyst at Gartner.

"Whereas as once we imagined a world in which individual users would have both a PC and a tablet as personal devices, we increasingly suspect that most individuals will shift consumption activity to a personal tablet, and perform creative and administrative tasks on a shared PC."

According to Gartner, Hewlett-Packard regained the top spot from Lenovo in unit sales in Q4 due to a stronger showing in the consumer segment, which dominates sales in the holiday season, but the company still showed no year-on-year growth.

Lenovo, despite its departure from the top position, showed the strongest year-on-year growth at 8.2%.

Dell was in third place, albeit with a 21% year-on-year dip in volume and Acer, down 11%, took fourth position.