Here's a pertinent question for you: What is the UI formerly known as Metro - and why should you care? The tech world is abuzz with speculation about Microsoft's latest operating system, Windows 8. And let's face it, as the latest and greatest from software giant Microsoft, it is a big deal. The company's not only divorcing the old Windows OS, but is also entering into competition with its own customers with a Microsoft-manufactured tablet PC.

So, what's coming to a PC near you? Read on to learn more about Windows 8 and the user interface with the trendy (but short-lived) name. (For some background reading, check out 10 Things You Need to Know About Windows 8.)

The Lowdown on Windows 8

While every Windows update has come with its share of complaints from users, the last few Windows operating system launches have remained substantially the same in basic operation. Windows 8 promises to be something completely different, as Microsoft tries to enter the explosively growing tablet PC field with a platform designed to unify desktops, laptops and tablets.

But despite the cool, sleek new look this OS clearly sports, early adopters are throwing up all sorts of potential red flags about this vast departure from Windows protocol. These include some non-intuitive controls, an interface where it's easy to accidentally switch screens and hard to go back, and the absence of the ubiquitous "Start" button, which may make this crossover platform a potential struggle for PC users.

What Happened to "Metro"?

It seemed like a pretty solid label - kinda catchy and easy to remember. So why did Microsoft retract Metro, leaving the new UI nameless for now? Speculation leans toward a potential legal problem, as the Metro handle may be owned by another company.

However, Microsoft issued a statement to the effect that Metro was a code name from the beginning, and was just being used so that developers had something to call the system. In August 2012, Microsoft announced that it planned to replace Metro with Windows 8 in marketing materials, although "Modern UI" appears to be the term that developers who plan to build software based on this OS are using.

How the Interface Works - and When It Doesn't

At a glance, it's easy to tell that the nameless UI was designed with smartphones and tablets in mind. Instead of the traditional desktop, there's a bunch of colorful, interactive tiles that show progress and updates to various applications. And these tiles are (arguably) a great feature for touch screen users.

The problems arise when you try to use a mouse and keyboard. According to many reviewers, using the UI on a desktop or laptop is an exercise in frustration. That's why Windows 8 actually uses two interfaces - the new Windows 8 version, and a desktop similar to Windows 7.

The first problem is that clicks and taps in the new UI don't work the same way on touch screens and traditional screens. That could be confusing for users who are operating the system on both. Also, many critics agree that Windows 8's touch controls aren't as intuitive as they should be, and some even require a strange version of two-fingered, slide-and-tap Twister to get what you want.

Second, when you're in the new UI on a PC, the system seems determined to boot you into the 7-esque setup. Click on the wrong app, and you'll find that all the pretty tiles have vanished.

The Start Menu Boogie

Accessing the start menu, which doesn't exist on the UI home screen, also requires some non-intuitive moves. You can pop up a thumbnail by hovering your pointer over the lower left corner of the screen, where the start button used to be.

However, the thumbnail is interactive. If you click on it, the UI will start the app that you pointed to, instead of showing the menu. To get to the actual start menu, you have to click off the screen while the thumbnail is up. Convenient? Not really, especially for long-time Windows users who are practically programmed for the old start menu setup.

Wait ... What Happened to My Program?

The dual interface in Windows 8 can cause a lot of problems, especially for longtime Windows users. If you're having trouble with the Windows 8 UI, you can just switch to the more familiar interface by pressing the Windows key (who uses that button anyway?). But, if you change interfaces, any program you launch will start over from scratch, instead of picking up from where you left off in the other UI.

What's more, there are some things you can only do from the new desktop, and others you can only do when using the traditional desktop, which means that switching is sometimes necessary. If you're not careful, whatever you've been working on can disappear, and finding it again can present quite a challenge.

Will Microsoft Work Out the Bugs?

Among those who have taken early test drives of Windows 8, there is hope that the software will come with improvements over the consumer preview. This OS is widely viewed as a make-or-break platform for Microsoft, which has lost ground to Apple and Google on the device front, so the company's incentive for presenting a polished product at launch is certainly there.

If Microsoft can smooth out the PC experience for the new UI (and maybe come up with a decent name), they have a shot at continued dominance. On the other hand, if consumers aren't convinced by Windows 8, we may see far more switches to the competition, and the possible toppling of a long-standing software titan.