For example, if you're running Microsoft Word with three open windows, you'll see a stack of three Word icons. Hover your mouse over the stacked icons, and thumbnails of all the open windows appear above the taskbar. Hover your mouse over any one of those thumbnails, and it displays at its full window size. To go straight to any window, click any of the thumbnails or windows. You can also close any window directly from its thumbnail by clicking a small red X that appears on the upper-right portion of the thumbnail.
Internet Explorer, Windows Explorer and Windows Media Player all have icons permanently pinned to the taskbar by default. You can pin any other application to the taskbar by dragging its icon to the taskbar.
What happens if you've got an application with too many open windows to fit as thumbnails across the taskbar? That's when "taskbar thumbnail overflow" takes over. When you hover your mouse over the application's taskbar icon, a list of files appears rather than individual thumbnails. The list still works like the thumbnail view -- highlight any file on the list, and it appears at its normal size, just as it would in a thumbnail view. You can also close any window by clicking a small X, just as in thumbnail view.
It may take longtime Windows users some time to get used to the new taskbar, but when they do, they'll find it a significant productivity boost, particularly when multiple applications with multiple windows are open. When this happens in Windows Vista, the taskbar soon gets cluttered with too many icons, and it is quite difficult to find the window to which you want to switch. In Windows 7, you can find the right window almost immediately by hovering your mouse over the proper application's icon.
In fact, it's superior to the Mac OS X Dock, from which it takes its inspiration, because in the Dock, you don't get a thumbnail view of all your open windows in an application. Of course, the Dock and Mac OS X Exposé have plenty of nifty tricks that the new taskbar doesn't, such as a quick way to see all of your open windows arrayed nicely against the desktop. In the next version of Windows, Microsoft would do well to steal some ideas from Exposé.
Putting the Jump List through its hoops
The taskbar has an associated feature called Jump Lists that makes it even more useful. When you right-click an application's icon in the taskbar, a menu appears of actions associated with that application -- and the list varies according to the application. For example, when you right-click Microsoft Word, you'll see a list of recently opened files, but when you click Internet Explorer, you'll see a list of your most frequently visited sites.
In addition to lists of files, you'll see tasks you can perform. For example, if you right-click on Windows Media Player, a task will let you play music. You'll also be able to close all open windows or pin the program to the taskbar if it's not already pinned there. (When you run a program that is not permanently pinned to the taskbar, the program's icon shows up in the taskbar for as long as the program runs. Once you stop running a nonpinned program, it vanishes from the taskbar.)
Similarly, recently used programs that appear on the Start menu each offer a list of recently opened files, the same as the one that shows up for applications on the Jump List. An arrow appears next to applications that use this feature. Click the arrow to see the list, then click any file to re-open it.
The new taskbar and Jump List have some hidden features. For example, you can manually pin files to a Jump List for a program that normally doesn't handle that file type by simply dragging the file onto the program's icon on the taskbar. You can then open the file using the program to which it has been pinned. It's a simple way to open a file using an application that normally doesn't handle that file type, without being forced to permanently change the file association.
Remote Desktop Connection users will be pleased to see that when you pin the Remote Desktop Connection icon to your taskbar, it includes all of the remote desktop connections you've saved in the Jump List. That makes it much easier to take control of remote PCs on your network.