Windows 10 Lean (Premium)

Windows 10 build 17650 contains a new product SKU that is currently identified as Windows 10 Lean. What is this thing?

Windows 10 Lean was first sighted by Lucan on Twitter, I believe. Based on the shots he provides, it appears that the SKU replaces Windows 10 S in the list of available choices, and he confirms that the system boots into S mode when installed.

But there are some major differences between Windows 10 Lean and last year's Windows 10 S. Most notably, the install is about half the size of a normal Windows 10 Pro install, and takes up only 2 GB or so on disk. Desktop application installs fail without the customary S mode warning dialog. And Edge, the only available web browser, can't even download files.

From what I can tell---I've not used this Windows 10 SKU yet myself---Windows 10 Lean is a more aggressive take on Windows 10 S, one that more completely "removes" (mostly hides) the Win32 world from the system, and from the user.

We can debate the need for such a thing, of course. But the big question, for now, is simple. What is this thing?

I have a theory.

Windows 10 S was always aiming at a future in which Microsoft could finally shed the Win32 legacy past of Windows and emerge with a more modern platform that would better fit within the functional and security needs of mobile devices and software delivered as a service. We could logically view the initial release of this system---which, you'll recall was first named Windows 10 Cloud---as an experiment. An experiment to see whether users would accept the restrictions of S mode on traditional PCs.

That experiment failed because Windows 10 PC users---get this---expect to run the familiar and necessary Windows applications that define this platform. A Windows that cannot run Windows applications is not Windows, arguably.

But there is a coming new mobile platform, based on Windows 10, that will run on new mobile devices like Andromeda. And my guess---it's literally only a guess---is that Windows 10 Lean (a name that will surely change) is for Andromeda.

It makes sense. Saving a paltry 2 GB of space on a modern Windows 10 PC but taking away Windows desktop application compatibility is as much of a non-starter as Windows 10 S was. But slimming down Windows 10 so that it runs on a new class mobile device makes plenty of sense. Especially when you consider that running desktop applications on such a system makes no sense at all.

So we'll see how this evolves. Perhaps Rafael can take a deeper look at Windows 10 Lean and plumb it for more details. For now, though, my bet is on Andromeda. And a Fall 2018/Redstone 5 timeline for both releases makes tons of sense.