Budget contraints and a move to use repurposed PCs and Chromebooks affected sales in the third quarter.
IDC said its overall forecast for the year will fall by over six percent compared to 2014.
But the market research company believes that shipments will grow between next year and 2019.
HP kept its lead in the market, with 26.9 percent. But hot on its heels was Dell with a 26 percent share. Ncomputing, Centerm, Igel and others made up the total figure.
HP’s share fell by 8.2 percent in the quarter, while Dell fell by 10.6 percent.