Could weak Windows 8 sales spell holiday trouble for Best Buy?

Probably not the start Best Buy had hoped for.

The initial sales numbers for Windows 8 devices are out and they don't look good. Since Microsoft debuted its latest operating system on Oct. 26, Windows device sales have fallen 21 percent compared to the same period a year ago, according to the NPD Group.

Windows 8 has captured only 58 percent of Windows unit device sales, far less than the 83 percent for Windows 7. NPD says Windows 8 tablet sales have been "non existent," accounting for less than one percent of all Windows 8 device sales.

"You would like to see some kind of acceleration," said NPD analyst Stephen Baker. "We didn't see any impact."

So why does this matter to Best Buy? The consumer electronics retailer, the country's largest seller of PCs, typically gets a big sale lift from the release of a next generation Windows operating system. Best Buy especially hoped Windows 8 would give a sizable boost to the key holiday shopping period. At a recent investors conference in New York, top executives noted the retailer carries 45 Windows products that are exclusive to Best Buy, including 28 touch screen devices.

Best Buy spokeswoman Amy Von Walter said Windows 8 is such a unique system that it will take time for consumers to digest it.

"We always knew that Windows 8 was going to be a long term proposition," she said. "Unlike other new devices, Windows 8 will be rolled out over several months."

Baker said weak initial sales doesn't necessarily mean a bad holiday season. For one thing, sales of more expensive Windows 8 notebooks with touch screens have been strong, helping Microsoft to establish a foothold in the premium segment normally dominated by Apple.

"The most expensive [Windows 8] products did the best," Baker said.

In fact, Best Buy said sales of Lenovo's Yoga laptop have been strong, said company spokesman Jeff Haydock.

"Overall, we are pleased with Windows 8," Haydock said. The devices "have performed within our expectations of the launch. We have also seen increased computing traffic to our stores and online."

With its radically designed interface, Windows 8 may also offer Best Buy the chance to do what it normally does best: explain complicated technology to consumers. Von Walter said the company devoted 50,000 hours training Blue Shirts on the new technology.