Windows 8 was an ambitious operating system. Microsoft's goal was, and still is, to have a single operating system that can span the traditional PC, the tablet, and everything in between.

To do this, the company introduced a new kind of application—the "Modern" or "Metro" style application. It created a new style of interaction—an edge-based UI for touch users, a hot-corner based one for mouse users. And it developed a new application launcher—the Start screen. Microsoft retained the familiar Windows desktop for running traditional mouse and keyboard driven Windows software.

Windows 8 worked. It was a viable operating system, and in broad strokes, it fulfilled Microsoft's dream of one operating system for tablets and PCs. But Windows 8 was far from perfect. Its problems were in three main areas.

First, the touch interface was in many ways incomplete. There was a nice touch-friendly settings app, for example, but it couldn't be used to configure most system settings. Instead, you had to use the desktop Control Panel.

Second, it did essentially nothing to marry the new touch UI to the old desktop. Both are important, and both have a role to play, but in Windows 8, the two lived in almost entirely separate worlds, with different styles of interaction, different appearances, and different capabilities.

Third, and perhaps most unforgivably, it did almost nothing to teach people how to use it. Windows 8 introduced a bunch of new concepts and new ways of using the operating system, but it didn't tell users about any of them.

Most (in)famously, Windows 8 removed the Start button, a button that had been a fixture of the Windows landscape for 17 years. There was still an action that was semantically equivalent to clicking the Start button—clicking the bottom left corner of the screen—but the button itself was missing. And rather than telling new users "Hey, you have to click in the bottom left of the screen now," Microsoft left them high and dry.

On top of all this, Windows 8 suffered from the typical problem faced by new platforms: it just didn't have many "Metro" style applications that were worth a damn. Disappointingly, this included the built-in, first-party applications. Core apps such as Mail and Music were weak at best.

These poor applications compounded Windows 8's problems because they meant that there was no real incentive to learn one's way around the new operating system. The three issues above could probably be overlooked if there were a rich family of must-have Metro applications to run. But there weren't. The Windows apps that people want to use were desktop apps anyway.

As such, Windows 8's novel features were a hard sell. It required you to learn new ways of doing things, and there was no meaningful payoff. Some of the new ways were a bit better than Windows 7; others were a bit worse. For many, even though Windows 8 included plenty of desirable under-the-hood improvements and enterprise features, it wasn't worth making the switch.

On top of the new interface and applications, Windows 8 introduced one more thing: a new approach to updating software.

Microsoft's traditional approach is to produce major updates every three or so years. But the competitive landscape has shifted. iOS and Android are updated every few months. Web browsers—from Mozilla and Google, at least—are updated every six weeks. Online services in the cloud are updated on a near continuous basis.

Infrequent major updates aren't enough to enable Microsoft to keep pace with these competitors.

So Windows 8.1 is here just a year after Windows 8. This update—free to existing Windows 8 users—doesn't fundamentally alter any of the objectives or design goals of Windows 8. Microsoft still wants to have one operating system that can span tablet and PC—and, if one looks further into the future, perhaps even the smartphone, too. But Windows 8.1 is nonetheless a surprisingly substantial update to Windows. It rounds off many of Windows 8's rough edges, providing a more coherent, better-designed working environment.

A tour around Windows 8.1’s refreshed user interface

Windows 8.1 looks a lot like Windows 8, but it's Windows 8 with a lot of spit and polish. The improvements start right at the lock screen. In addition to the previous swipe down to unlock, you can now swipe up to get instant access to the camera app.

The centerpiece of the Windows 8 user interface is the Start screen:

The basic concept of the Start screen is unchanged from Windows 8. The differences are in the details.

More personal

The Start screen was always meant to be personal, with the live tiles (and hence, updates) that you care about placed most prominently. Windows 8's attitude toward this personal nature was, however, inconsistent. It didn't respect the user's ownership of the Start screen. Any time you install a new app on Windows 8, its tiles get put on the Start screen automatically. For desktop apps, this could result in dozens of tiles being spewed across the screen that you then have to tidy up manually.

In Windows 8.1, the Start screen is squarely the user's. OK, there are a bunch of default live tiles for new accounts, but beyond those, the tiles are up to the user. Installing software won't dump a mess of tiles everywhere.

Those tiles that you do put on the Start screen pick up a couple of extra sizes. Windows 8 had just two sizes: the half-width square and full-width rectangle. Windows 8.1 adds a smaller square for high-density app launching and a large double-height square for showing more information.

A bunch of new background images for the Start screen have been added. Some of these are simple static images that have the same kind of parallax scrolling effect as in Windows 8. Others are more exciting, with animations and movement. Windows on a cityscape light up periodically, robots fly around, and cogs spin as you scroll.

There's also a new option to use the same background behind the Start screen as you have on the desktop. This apparently small change has a surprisingly profound effect on the feel of the operating system. If you use desktop applications (whether exclusively or in conjunction with Metro ones), the shared background makes the Start screen—and by extension, the Metro world—feel like it's actually related to the desktop and not a completely alien addition.