WIndows Minimize and Maximize Shortcuts
minimizes all open windows,
Windows D shows your desktop.
"These results look similar, but they're slightly different; Windows M minimizes all windows that support the command, while Windows D actually raises the desktop to the top.) This is a great one for when the boss pops up in your cubicle. Once the boss gone, hit Shift Windows M to bring up your minimized windows, or Windows D to drop your desktop back down again."