Windows 8

Windows 8 tries to get you to tie your Windows login to your Microsoft account; it’s optional, but if you do link the two, the Windows login and password serve as your Microsoft account login and password. Permitting this link allows tighter integration with the remote and cloud-based features of the new OS.
Windows 8 is designed to be part of an ecosystem, alongside Windows Phone and Windows RT. Microsoft believes in this idea so strongly that it has made the Windows 8 user interface (previously called Metro) the primary interface for Windows users. Computers with the new operating system installed will boot into the Windows 8 interface; the OS offers no built-in way to set it to boot to the traditional Windows desktop.
The Windows 8 interface acts as the Start menu now. Instead of looking as columns of small icons that pop up when you click the Start button, all your applications show up as tiles on the Windows 8 Start screen. You can also look for an application by typing its name when you’re in the Start screen; the results list auto sorts as you type more characters. The screen exists as a launch pad for applications, not as a desktop replacement. That concept is simple to forget, since the Start screen takes up the entire display. Even so, Windows 8 apps consume the entire screen, whereas desktop applications can still run in a window on the desktop. On the other hand, not all desktop applications appear on the Start screen by default. Some accessory apps, such as Paint, live in the Apps screen. You can force these programs to appear in the Start screen by right-clicking them to select them and then clicking Pin to start at the bottom of the screen. However, getting to the Apps screen is simple: Right-click a blank area in the Start screen and then click the all apps icon at the lower right.
You cannot boot directly into the desktop, since Microsoft wants the Start screen to be users’ first experience with Windows 8. For most people, this restriction may not be an issue, but certain vertical applications need to boot directly into a desktop environment. Until Windows 8 versions of such programs become available, users requiring vertical applications should stick with earlier versions of Windows. If all you need to do is launch an application, you can simply click its tile in the Start screen. If you need robust file management and navigation features, you have to access the desktop. After you boot the machine, pressing the Windows key sends you to the desktop. Sadly, the Windows key isn’t consistent in this behavior: If you’re in an app, pressing the Windows key always returns you to the Start screen. Press it again, and you’re in the most recent Windows 8 app. Instead, to move to the desktop consistently, you need to be in the habit of pressing Windows-D. Another option is to move the pointer to the lower left of the screen and click there.
The PC you own today almost certainly lacks a touch screen. You may have a laptop with a touchpad, but most existing touchpad’s can't take full advantage of