Microsoft's latest Windows 8 operating system has failed to drive the sale of new PCs over the holiday season according to the president of Acer.

Speaking to the New York Times, Emmanuel Fromont, who heads the computer maker's American division, said one reason for the slow uptake of Windows 8 machines was because the unfamiliar design was making buyers cautious.

"There was not a huge spark in the market," Fromont said. "It's a slow start, there's no question."

The comments add more bad news for Microsoft which has also been struggling to shift its new Windows RT-based tablet, Surface.

Microsoft launched Windows 8 in October, a completely revamped version of its famous operating system, in the hope of regaining control of a computer industry now increasingly dominated by touchscreen devices.

Its redesigned interface allows for dual touchscreen and traditional desktop use and was released alongside Windows RT, specifically for tablets, and Windows Phone 8 for smartphones.

However, the bad news for Microsoft came early with CEO Steve Ballmer, as long ago as November, telling French news site Le Parisien that sales of the Surface tablet were modest. Two weeks later, David Chang, CFO at Asustek Computers, told the Wall Street Journal that demand for Windows 8 was lower than expected.

Microsoft has blamed a sluggish market for PCs overall for the poor sales. The company reported that 4 million, out of a user base of 1.25 billion, upgraded to Windows 8 in the first four days of its launch.