The numbers are starting to come in, and they don't look good for Microsoft. Two reports last week pegged the sales decline for the PC market's first quarter at either 14 percent or 11 percent, and everyone's blaming Windows 8 for the situation.

"It's brutal," said Bob O'Donnell of the research firm IDC. "These are disastrous numbers. Huge. Not only has Windows 8 not helped, but it's actually hurt PC shipments."

The numbers initiated another round of Windows 8 doomsaying, and now people are actively debating whether or not the operating system is "Microsoft's biggest failure ever."

Sure, but just because people ask the question doesn't mean the answer is yes. However, the simple fact that people are wondering if Windows 8 is worse than Vista or Zune is pretty damning.

Motley Fool's telecom analyst Andrew Tonner took on the question head-on in a recent video.

While there may certainly be macroeconomic reasons for slowing PC sales, Tonner said, "It is also clearly based on the lack of success of Windows 8." Many analysts expected Windows 8 to reinvigorate the PC market, boost sales and begin another healthy refresh cycle for PCs, he added, but that is "clearly not the case. People simply don't seem to like the platform very much."

But the negative reaction isn't just a bad sign for PC makers, it also creates ripple effects for Microsoft's other ambition: to expand in the mobile marketplace. It needs Windows 8 to do that. This is the first time Microsoft has moved toward a unified OS across mobile and PC, and if it fails, the company will find itself in a precarious position. There's always the chance that Windows Blue (8.1) could make the OS appealing enough for sales to pick up, but even that won't happen until much later this year.

Tonner doesn't come out and say Windows 8 is a huge failure, but by the end of the video it's easy to see he's not confident in Redmond's strategy or ability to pull through:

"There's a reason this company [Microsoft] basically has generated zero returns for investors over the last ten years, and that's because they simply don't get where technology is going any more."

"They're entrenched where it's been, but its future is not looking good for Microsoft."