In Microsoft's 37 year history, this could be its most important software launch. PC sales are on the decline and Microsoft has lots of ground to make up in the tablet and smartphone market.
Microsoft made Windows 8 to turn around its fortunes in both markets. That's why it's faster and lighter than previous Windows versions. It also has a radical new user interface that Microsoft says works well on both computers and mobile gadgets.
Of course, Microsoft has to say that to make sure it sells. The real question is if Windows 8 can actually deliver for you, the user.
The first thing to understand is that when I say Windows 8 has a radical new interface, I'm not saying it's like Windows 7 with a paint job.
The Start Menu that dates all the way back to Windows 95 is gone. In its place is a touch-friendly Start Screen.
The Start Screen uses the Modern interface that Microsoft originally developed for Windows Phone 7, and is using for Windows Phone 8 and the upcoming Xbox. It uses colorful live tiles to launch programs and display real-time information.
You can have a weather tile that shows you the weather, an email tile that shows you incoming email, and so forth. Once you get used to it, it's actually a flexible and powerful system.
Well, it is if you have a touch-based computer or tablet. The Start Screen wasn't really meant for mouse and keyboard. It's usable, but it isn't intuitive. You can see it in action with my Windows 8 Preview video.
There is a Desktop mode that works just like Windows 7 (minus the Start button, of course). So Windows 8 isn't completely foreign, but long-time Windows users will have some adjusting to do. For those who are happy with Windows Vista or 7, my advice is to stick with what you have. On older hardware, Windows 8 will only be a hair faster, and you'll have to learn a new way of doing things.
If you're buying a new computer, you really don't have a choice - they'll all have Windows 8 installed.
But if you do buy a computer with Windows 8, all is not lost. With a bit of instruction, you can learn how to use it just as effectively as you use your current version of Windows.
Download my Essential Windows 8 Quick Start Guide for all the information you need. It will walk you through using the Start Screen, the Desktop, the new Charms system, and where to find the settings that got hidden away. You'll be a Windows 8 pro in no time!
I said earlier that Windows 8 works best on tablets. In fact, Microsoft released its own tablet line called the Surface. You can watch my Surface video review at TVKim.com.
The one thing you're going to hear me repeating a lot is that not all Surfaces are the same. There are two types: Surface with Windows RT and Surface with Windows 8 Pro.
The Surface RT is Microsoft's answer to the iPad and Android tablets, while the Surface 8 Pro is more like a laptop.
The thing to remember with Windows RT is that it looks like Windows 8, but it isn't. It will NOT run your Windows programs. It only runs apps from the Microsoft App Store - and there aren't that many right now.
If you want a tablet that runs Windows programs, you'll have to wait for the Surface with Windows 8 Pro. Unfortunately, that isn't out until early 2013.
The Surface isn't the only news in mobile. Here's some more that will interest you.