For the first time in fifteen or more years, Redmond faces a genuine challenge to its Windows desktop monopoly. The threat isn't coming from Linux or from Mac OS X or from any other operating system. It's coming from a whole new computing concept: the "post-PC." The worry is that upstart tablets threaten to drive the computer out of the home, taking the Windows operating system with it.

It's not just Microsoft that's facing a tumultuous revolution, of course—the PC as a platform, as a concept, is equally under attack. But the biggest loser from this new world order will surely be Microsoft. Hardware makers can just switch to making new hardware, but Microsoft needs that hardware to run Microsoft software, and the company has been consistently unable to crack the tablet market.

Microsoft is no newcomer to the tablet market; in fact, the company has been in the tablet market longer than almost anyone else. But success in this market has been hard to come by. Microsoft's hope, the PC's great hope, is Windows 8. With Windows 8, Microsoft needs to build not just a Windows that PC users want to use; it needs to build a Windows that can succeed in the post-PC world.

Perseverance



One way or another, Windows has run on tablets for most of its existence. Windows for Pen Computing was an extension to Windows 3.x that added support for styluses, an on-screen keyboard, and handwriting recognition—and it appeared all the way back in 1991. A followup, Windows for Pen 2.0, shipped for Windows 95. Neither found much success outside narrow vertical markets, where the ability to write on the device or to use it while standing were particularly important.

Still, Microsoft persevered. Windows XP Tablet PC Edition appeared in November 2002, and was updated in August 2004 to Windows XP Tablet PC Edition 2005. Though these editions boasted improved handwriting recognition, and though Microsoft shipped its well-regarded tablet-friendly app OneNote in 2003, market impact remained slight.

The same pattern continued with Windows Vista, and then with Windows 7. Tablet features are no longer branded separately, instead serving as part of the standard operating system. But that doesn't mean they're widely used.

Competing approaches

For two decades now, Microsoft has had a consistent tablet ideology: tablets are PCs. They run PC operating systems, they run PC software, they have the full flexibility that the PC has. This point was explicitly made just last month, when Andy Lees, President of the Windows Phone Division, said:

We view a tablet as a sort of PC. We want people to be able to do the sorts of things that they expect on a PC on a tablet, things like networking to be able to connect to networks, and utilize networking tools, to get USB drives and plot [sic] them into the tablet. To be able to do things like printing, all of the things using Office, using all of the things you would expect from a PC and provide a hybrid about how you can do that with the tablet, as well.

Apple's iPad comes at the tablet question from the other direction. For the iPad, Apple took its successful smartphone operating system and scaled it up for larger screens. All the limitations of the smartphone operating system were retained on the larger device. The result? The iPad isn't a PC. You can't run regular software on it—you can't even run software that hasn't been explicitly blessed by Apple. There's no user-visible filesystem. There's little scope for attaching peripherals. Multitasking is restricted. Even the user interface is severely limited, with its full-screen single-tasking concept.

Yet the iPad has been hugely successful. It's slim, lightweight, goes for many hours between charges, and it's easy to use. It's also built around a touch interface; as good as a mouse and keyboard are (and for serious text entry or complex software, they really do work very well), they're also very limiting, as they're awkward to use when not sitting down with the device on a lap or desk. Touch makes the iPad usable standing up, lying down, or slouching on the sofa. Is the iPad a limited device? Sure. But the limitations don't really matter for the things people use iPads for; millions of people have found that the iPad's upsides more than outweigh its flaws.

Welcome to the post-PC era

So successful has the iPad been—and so unsuccessful were Windows tablets of old—that the iPad's flaws and limitations have been extolled as virtues. Steve Jobs, when announcing the iPad 2, described the new "post-PC" world:

That these are post-PC devices that need to be even easier to use than a PC. That need to be even more intuitive than a PC. And where the software and the hardware and the applications need to intertwine in an even more seamless way than they do on a PC.

The limitations that iOS imposes on users and developers alike are assumed to be essential to the creation of an effective tablet; the restricted software, the limited connectivity, the rigid user interface constraints, all are required to sell tablets. This is the post-PC world: sealed systems that trade flexibility and connectivity for appliance-like simplicity, casual interfaces, and convenience.

The iPad is king of this world, and though PC sales still dominate, they're flat while tablet sales are growing fast—so fast that the post-PC is widely seen as a threat both to Microsoft and to the PC as a whole. Microsoft can survive short-term difficulties in the smartphone market, as smartphones aren't really PC substitutes. A failure to tackle the tablet market, on the other hand, could be disastrous, a point the company has noted in its most recent 10-K filing.

Avoiding the beaten track

The decision to call, or not to call, a tablet a "PC" goes beyond mere branding. It influences the entire approach that Microsoft takes. It colors the user interface design, the sales model, the hardware requirements, the options available to system integrators. Redmond has considered scaling up its smartphone platform the way Apple and Google have both done, but as Lees put it:

Now, a lot of people have asked me, are we going to produce a phone that is a tablet? You know, are we going to use Windows Phone 7 to produce tablets? Well, that is in conflict with this strategy.

This does make some sense. The tablet's size, which has a considerable influence over interface complexity, is clearly more PC-like than it is smartphone-like. The usage model of the tablet is also closer to that of the PC than it is to the phone. Smartphone usage is brief and focused: sending a text to say they you're going to be late, checking a map to see just how lost you are, finding a restaurant. Even smartphone games tend to have lots of short levels so that you can dip into them during an idle moment, then quit without losing progress.

Tablets, due to their size, are never going to be the first choice for that kind of instant gratification. But the tablet remains a much better fit for longer, more considered use cases: settling down with a book or a movie. Writing a letter. Recreational—rather than informational—browsing. This usage style is a lot more PC-like than it is smartphone-like, and an interface designed around smartphone use—quickly jump in, find what you want, and get out—may not be the best option for a tablet.

Still, this tablet-as-a-PC model hasn't worked well despite 20 years of trying. Microsoft's decision to stick with it might look like a mistake—why would this approach start working now when it hasn't before?—but signs suggest it might be more successful this time around.