The Windows desktop is at once the most important and least important part of the Windows experience. On the traditional desktop and laptop, it's fundamental; it's where most apps run, and it's where most users want to be. The perceived downplaying of the desktop in Windows 8 was one of the many reasons that desktop users were unhappy with the operating system.

But on the tablet, the desktop is a liability. Small, fiddly apps that aren't designed for fingers do not make for a good tablet experience. Every time a tablet user has to use the desktop—and on Windows 8.1, they will have to do so at least some of the time—then that tablet user has to suffer an experience that is, at its heart not a tablet experience, and it's no fun at all.

The Windows desktop: totally essential in some situations. Totally unwanted in others.

Microsoft does have a desktopless Windows—it's called Windows Phone—and many wanted the company to use the operating system as the basis for its tablet platform. Through necessity, Windows Phone is a complete touch environment, with every feature usable with fingers alone. When Windows 8 materialized, with the full desktop in tow, the reaction was bemusement. Sure, technically you could add a mouse and a keyboard to a tablet and use that desktop for desktop software, but that was hardly the point of tablet systems.

This was doubly so on the ARM-powered Windows RT tablets. These had the full desktop, but unlike their x86 counterparts, couldn't even run desktop software. The desktop was a necessary evil because the touch-friendly Metro environment lacked things like a complete settings app, a competent file manager, and any kind of productivity software.

With Windows 10 Microsoft is going to make a desktopless version of Windows. At its Windows 10 event last week Microsoft said that there would be an 8 inch cut off point. At 8 or more inches, devices would run regular Windows 10.

Below 8 inches, however, and things would be a little different. Windows 10 for phones would, like Windows Phone 7 and Windows Phone 8 before it, include Office. That is, it would include the new, designed for touch Office apps that are not entirely dissimilar from the apps that already exist on iOS and Android. The phone version won't include a desktop, which is no great surprise because the phone OS never has.

In parallel to this will be an iteration of the existing Windows for Small Tablets version. Designed for tablets smaller than 8 inches, this version will be very similar to Windows 10 for phones (albeit lacking a dialler), and it was confirmed yesterday by Windows design lead Joe Belfiore that it won't include the desktop.

Any existing sub-8 inch devices running Windows 8.1 will retain the desktop when upgraded to windows 10; it's only new devices that'll be desktop-free.

With Windows 10, Microsoft can actually do this because Windows 10, like Windows Phone, but unlike Windows 8.1, is going to include a complete touch environment. A good example of this is the new Settings app. This is a universal app—substantially the same code is used on PC, tablet, and phone—and the intent is that by release time, the Settings app will offer control over every setting that a PC or phone will need. It's not quite there yet in the preview, but it should be ready for release.

Symmetrically, taking the decision to ship a version of Windows without the desktop forces Microsoft to make sure that Windows is fully usable without a desktop. In a way, it keeps the company honest: it has to treat touch accessibility as essential, and not merely desirable.

While 2-in-1 style devices such as the Lenovo Yoga series have found some success on the market, pure tablets, especially smaller ones, have been crying out for this kind of operating system. The Windows desktop simply isn't enjoyable to use on 8 inch or smaller devices. A desktop-free version of Windows will provide a smoother experience.

A desktopless Windows might also make sense as an upgrade for Windows RT devices. Windows on ARM hasn't been an overwhelming success—not least because Intel's heavily subsidized processors have enabled Intel-equipped tablets to be price competitive with ARM ones—but abandoning the architecture entirely seems hard to justify. ARM continues to be critical in the smartphone space, and it's not clear how Intel plans to remain price competitive in this field.

As such, Windows on ARM may gain some relevance in the future. Keeping it on life support as a hedge against, for example, Intel dropping its subsidies (and hence, cheap prices) to ensure that Microsoft has some option in the $1-200 market would seem sensible, and desktopless Windows with touch Office would be the obvious operating system for this market.

This may not quite be what people hoped for in the early days of Windows Phone—a tablet operating system built on the same foundation—but it's not a million miles away. Microsoft just took a roundabout way of getting there: turning Windows into Windows Phone first.