Microsoft is so happy about Windows 10 that it is releasing seven different versions. The new OS will launch this summer, and the first choice interested consumers will need to make is which "flavor" to buy. That choice shouldn't be made lightly, because Microsoft says Windows 10 is the end of the line for what you might call "Windows Classic." In other words, you'll have to live with your choice for a while.\nIn the future, Microsoft will distribute Windows upgrades in a way that's similar to how Apple upgrades OS X and Google refreshes Chrome, which is to say a lot more frequently than in the past. Unless Microsoft changes course (and it often does) there won't ever be a "Windows 11" \u2014 just frequent upgrades to Windows 10.\nMicrosoft has described this model as "Windows as a service" to demonstrate that it will be constantly refreshed the way cloud-based services are, even though the OS resides \u2014\u00a0as it always has \u2014\u00a0locally on the device.\nHow much will you pay for each upgrade? The answer is unclear, but at some point Microsoft will likely say something like,"You got lots of free updates to Windows 10, the next one is on you." You didn't think it would be free, did you?\nStill, the new system makes sense, and if handled correctly it will be a good thing for consumers. Software changes very rapidly today; the days of waiting three years for a major upgrade and having to download humongous "service packs" are long gone, and it's good to see Microsoft recognize this reality.\nMicrosoft on Tuesday told the world in a blog post that it will sell seven versions of Windows 10: Home, Mobile, Pro, Enterprise, Education, Mobile Enterprise, and IoT Core. That's a lot of versions, and it's the largest lineup of Windows flavors I can recall.\nThe company said months ago that it plans to make Windows 10 available as a free upgrade for consumers running Windows 7, Windows 8.x and Windows Phone 8.1 for the 12 months following Windows 10's release. If you buy a new PC, it will include Windows 10, and the price will be baked in.\nHere are some details on the Windows 10 versions from Microsoft:\nWindows 10 Home is the consumer-focused desktop edition. It will include the Cortana digital assistant; Microsoft's new Edge browser; a Continuum tablet mode for touch-capable devices; Windows Hello (facial, iris, and fingerprint login features); and the ability to stream Xbox One games.\nWindows 10 Mobile\u00a0is the version for Windows Phones and small Intel- and ARM-based tablets. It will have the same universal Windows apps that are included in Windows 10 Home, as well as the new touch-optimized version of Office.\nWindows 10 Pro is a desktop edition for PCs, tablets and 2-in-1s. In addition to having all of the Windows 10 Home features, it lets you manage devices and apps, protect sensitive business data, support remote and mobile productivity scenarios, and take advantage of cloud technologies.\nWindows 10 IoT Core, as its name suggests, is for small devices that are part of the so-called Internet of Things.