August 28, 2012, 3:02 PM — If you want to get the most out of your PC when you're at your desk, having multiple displays is a tremendous productivity aid. Putting your email, chat, and Web browser on a secondary display while editing documents on the primary one amplifies your ability to get work done.
Windows 7 offers multiple display support, but Windows 8 takes it to the next level. All you need to do is plug in a second display, then dive into your applications. It's worth taking a look at specific aspects of Windows 8's multidisplay support.
Inside Edge Detection
Windows 7 had limited support for edge detection in single-display mode. In the case of a multimonitor display, edge detection treated the entire display surface as one monitor. So if you wanted to throw a window to the side of the screen to take up exactly half the display, that wouldn't work if the edge was the "inside" of a two-display setup.
Windows 8 supports edge detection at the edge of all displays. For example, if you hover over the left edge of the right display (the inside edge), you'll still see the sidebar thumbnails of running applications.
If you hover the icon on the upper right corner of the left display, you'll see the Charms bar.
Just remember to hover the mouse cursor for a second or two at inside edges or corners to activate the effect. Note that shared corners or inside edge detection areas are only six pixels wide. You really need to be in that small area for edge detection to occur, as well as hovering the cursor for a few seconds.
Customize the Taskbar
Windows 8 now allows you to have individual taskbars on separate monitors. The default is to replicate pinned icons on all display taskbars. Two other options exist, which you access by right-clicking on the taskbar and selecting Properties.
If you prefer the Windows 7 method, you can even set up the taskbar so that it shows up only on the primary monitor.
Windows 8 adds a pair of new keyboard shortcuts to manage Windows 8--style apps in multiple displays, as well as supporting the Windows 7 shortcuts used for multiple displays. The Windows (or Win) + arrow keys still snap windows to one side or another. Win + PageDn (or PageUp) swaps full-screen Windows 8 apps to different displays.
Slideshows and Images
You can now show different background images on different displays. In fact, if you select multiple images, slideshows will show different images on different displays. Windows 8 will even try to be smart about what aspect ratios and resolutions to show if you're using multiple aspect ratios (say, one portrait-view and one landscape-view monitor).