When you open multiple windows on the desktop, it can sometimes be a challenge to view separate windows and switch between them.
You can use Peek to take a quick look at other open windows without clicking away from the window you're currently working on. Peek makes it easy for you to preview the contents of open windows and switch to the one you want.
Point to a program button on the taskbar that has open files.
Point to a thumbnail. All other open windows temporarily fade away to reveal the selected window.
To preview a different window, point to a different thumbnail.
To restore your desktop view, move the pointer away from the thumbnails.
To open the window you're previewing, click the thumbnail.
To learn more about Peek and other Windows 7 desktop features, see What is the Aero desktop experience?