The short answer to that question? We still don't know.
Microsoft released quite a few statistics about Windows in its earnings report this afternoon, but not the statistics that would give IT managers a real sense whether Windows 8 is going to keep the Windows PC at the top of the heap in personal computing.
The company said that it has sold 60 million Windows 8 licenses since launch, but that's the same statistic they gave at the Consumer Electronics Show in January.
To be fair, sixty million units is a big number. There's still no other single tech product that sells in such great numbers. By way of comparison, Apple sold about 48 million iPhones during the same period.
Still, we knew that already.
Then there's Windows Division revenue, which came in around $5.9 billion. That's up 24% from last year, which sounds amazing given that market researchers like Gartner saw a decline in PC unit sales during the quarter.
But that 24% includes revenue deferred from pre-sales of Windows 8 to consumers during the summer. Microsoft doesn't count that money until the product actually goes on sale . Subtract that out (along with some other adjustments to make the comparison apples to apples -- forgive the pun), and you actually have a 11% increase in revenue from last year.
That's still amazing given the well-reported troubles of the PC market.
Except there are also some other factors at play.
First, Surface. Microsoft sells the Surface RT for $499 and up -- a lot more than the estimated price of Windows on a new PC, which is probably around $100 (more or less, depending on the type of license sold). Microsoft hasn't said how many Surfaces it sold, but if the figure is around 1 million as analysts have estimated, that means at least $300 million in additional revenue from a product that didn't exist last year.
If Microsoft is simply replacing third-party PC sales with Surface sales, that's good for Microsoft as a company today, but not for the long-term health of the Windows ecosystem.
Second, retail sales. Every time Microsoft puts a new version of Windows on sale, it gets a spike from consumers buying copies to install on their old PCs. This spike usually peters out after a quarter or two. It can't be ignored, but it's got little to do with the long-term strength or weakness of Windows 8.
Finally, in the accompanying slide deck (downloadable here), Microsoft said that enterprise volume license sales were up "double digits," which is CFO-speak for at least 10%.
That probably means Microsoft is selling more Enterprise editions of Windows than it did last year. There are quite a few valuable features of Windows 8 that come only in the Enterprise edition, like Windows To Go (which lets employees boot Windows 8 from a USB drive). Windows Enterprise licenses also convey other benefits, like the right to buy a set of management and virtualization add-ons known as the Microsoft Desktop Optimization Pack, or MDOP.
Overall, Microsoft said that these three buckets -- "non-OEM revenue" -- grew 40% from last year. That's where most of that 11% growth came from.
That said, Microsoft also boasted that OEM revenue from Windows 8 sold on PCs from other companies like Dell, HP, and Lenovo -- that is, the biggest bucket for traditional Windows sales -- outperformed the overall x86 PC market.
In other words, Microsoft is doing better with Windows 8 than the broader PC market is.
Still, we don't know whether Windows 8 is accomplishing its main mission, which is to keep the Windows PC relevant as the world moves to mobile-first, touch-enabled computing -- what Steve Jobs called the "post PC era," and what Microsoft prefers to think of as the "PC plus" era.
The other very real possibility is that consumers will keep snapping up mobile devices with operating systems from other vendors, and use those for more and more tasks at work and at home, gradually consigning the Windows PC to a much smaller niche than it's occupied for the last 20 years.
That story will play out over years, not quarters.