Software giant Microsoft (NASDAQ:MSFT) made headlines earlier this week when it boasted 100 million license sales of Windows 8 since the controversial new platform launched six months ago. Microsoft also outlined its plan to release a public preview of Windows 8.1, codenamed "Blue," which may address some of the platform's weaknesses.

That's up from the 60 million figure that Microsoft touted in January. That's also roughly the same pace that the flagship operating system's predecessor saw when Windows 7 was unleashed upon the world back in 2009.

Keep in mind that these figures that Microsoft shares are based on sell-in to its distribution channel, which includes sales to retailers and OEMs. Some of these licenses are sold directly to end users, including upgrades, but most people generally don't buy copies of Windows directly.

When it comes to actual sell-through and consumer usage, Microsoft is likely doing much worse than its statistics would suggest. Moor Insights & Strategy principal analyst Patrick Moorhead estimates that 41% of those Windows 8 licenses aren't in play right now.

The analyst arrives at that figure by cross-referencing the 4.2% web usage that Windows 8 is fetching from Net Applications' data with the total 1.4 billion Windows PCs out there. That would put Windows 8 units in use at around 59 million, implying that the remaining 41 million licenses are sitting on shelves or within distribution channels.

There's other evidence to back up this notion. OEMs have noted that they're still working to clear out Windows 7 inventory, in part because consumers remain confused about Windows 8 as well as the lower price points that Windows 7 devices are now available at. Just this week, Toshiba exec Mark Whittard said that there was a "significant amount" of Windows 7 inventory still in the channel that the company needs to "sell through first."

Filling the channel is one thing. Customers actually using the product is another. Microsoft is bragging, but perhaps it shouldn't be.

Fool contributor Evan Niu, CFA, has no position in any stocks mentioned. The Motley Fool owns shares of Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.