Minimize all open windows in using Aero Peek
Aero Peek is a Windows interface feature that lets you "peek" at the Windows desktop, getting a quick view of it. You can activate Aero Peek if you left-click the bottom-right corner of your screen.
If you have several windows open at one time, you can minimize them by using Aero Peek (Show Desktop) icon on the Windows Notification Area on your taskbar. The Show Desktop minimizes all open windows so you can access your desktop.
To re-open all previously minimized windows, click the 'Show Desktop' icon again and they will all reappear.
Also, to view the Desktop without actually minimizing all screens, you can use Peek. Hover your mouse pointer over the 'Show Desktop' icon without clicking. This way, you can view your desktop momentarily without minimizing anything.
You can also press the keyboard shortcut Windows Key+D to get to the Windows desktop. After you're done viewing the desktop, if you press the same keys again, the windows will be restored to their original state.