Windows 8 Consumer Preview is one of the biggest changes that Microsoft has made to Windows, moving it from an operating system aimed at a single class of hardware (PCs and laptops) to one that spans a wide range of devices, including desktops, laptops, tablets and smartphones.

It's a gamble that only partially pays off. For tablets and smartphones, the new Metro interface is a clear winner: beautifully designed, simple to use, function-rich and offering a wealth of apps that bring information directly to users rather than requiring users to search it out.

For owners of traditional Windows-based computers, however, the results are mixed. Metro isn't as easy to navigate with a mouse and keyboard as it is with touch. In addition, the Windows Desktop is less useful in Windows 8 than it was in previous Windows versions for a number of reasons -- notably because the Start button has been taken away. As a result, Windows 8 feels like a transitional operating system, uneasily bridging the gap between traditional PCs and tablets, with more attention lavished on the latter.

For tablets and smartphones, the new Metro interface is a clear winner. Click to view larger image

Perhaps because of this -- and because, despite the growing popularity of tablets, most workers are still using desktop PCs and laptops -- I installed the Windows 8 Consumer Preview on a PC, and this review reflects its use on desktops and laptops rather than tablets.

I reviewed the Windows 8 Developer Preview when it came out, and this Consumer Preview is a considerably more polished piece of work. There have been many major interface changes, fixes and additions -- Microsoft claims that it's made more than 100,000 changes, although that's obviously impossible to verify. Key among the changes and additions are new navigation features, completely revamped Metro apps and the addition of "charms," which are tools that bring a variety of features such as Search within easy reach.

The Developer Preview was a hint of what the operating system would be; this Consumer Preview is a far more realized piece of work.

Welcome to Metro

Metro, which is patterned after the Windows Phone 7 interface, made its appearance in the Developer Preview, and it's seen considerable improvements, including the newfound ability to place apps into customized groups.

Windows 8 boots directly into the Windows 8 Metro Start screen. Rather than seeing the traditional Windows Desktop, you're greeted by a group of large colorful tiles, each of which is a separate app. (To show how Microsoft has relegated the Desktop to the sidelines, the Desktop is merely one app among many on the Start screen. It's also the only app that isn't written for Metro.)

Metro apps are "live" -- that is, they can grab information from elsewhere, such as from social networking services or other Internet locations, and use it and display it right in the tile itself. So the weather app, for example, displays the current weather, a stock app displays current stock prices, a calendar displays current meetings, and a social networking app (called People) can display the latest updates from social networking services. In this way, you don't have to open many of the apps to reap their benefits; all you need to do is glance at them on-screen. You can, of course, click on any app to launch it in order to get more information and interact with it.

Metro is very clearly designed for tablets, because the tiles are all quite large, even those that don't display changing information. There are so many tiles that they scroll off to the right of the screen. On a tablet, you use the swipe gesture to see them. On a traditional computer, you need to scroll to the right, which is a lot more awkward. Although the Metro start screen is aesthetically pleasing, I found myself longing for the Desktop's more efficient use of real estate; there, I could see all my apps on a single screen.

That being said, the Start screen is easy to customize, so you can make sure that all of the apps you use regularly are immediately visible. And you can remove apps pinned to the Start screen by right-clicking (or, on the keyboard, Ctrl-right-clicking); a menu appears at the bottom of the screen that lets you unpin, resize or uninstall the app. Not all apps can be resized, though -- Microsoft's cloud-based SkyDrive storage service can't, for example.

A menu appears at the bottom of the screen that lets you unpin, resize or uninstall the app. Click to view larger image

You can also put tiles into their own groups as an easy way to see related apps at a glance. Click a small icon at the bottom right corner of the screen and all the apps on the Start screen shrink into a small space. Move tiles anywhere you want on the screen, including into groups. Right-click a group to name it. Click anywhere on the Start screen and the tiles return to their normal size.