The Windows key or Windows logo key (in short WinKey, or rarely Flag key, Start key or Menu Key) which was originally introduced for the Windows 95 operating system , located in the bottom row of most computer keyboards is a little-used treasure. Don't' ignore it. It is the shortcut anchor for the lot of things.
Windows: Display the Start menu
Windows + D: Minimize or restore all windows
Windows + E: Display Windows Explorer
Windows + F: Display Search for files
Windows + Ctrl + F: Display Search for computer
Windows + F1: Display Help and Support Center
Windows + R: Display Run dialog box
Windows + break: Display System Properties dialog box
Windows + shift + M: Undo minimize all windows
Windows + L: Lock the workstation
Windows + U: Open Utility Manager
Windows + Q: Quick switching of users (Powertoys only)
Windows + Q: Hold Windows Key, then tap Q to scroll thru the different users on your PC.
Other than this it can also perform the following functions
Under Unix and Unix-like operating systems it is often used as the Meta key or Compose key. Desktop environments such as KDE and GNOME for GNU/Linux support it, though it may be necessary to configure its functionalities after installation. Free operating systems often refer to the key as "Super".
Apple's Mac OS X uses the Windows key as a replacement for the Command key if a third-party keyboard is used that does not include the latter.This sometimes leads to placement issues for users used to Apple keyboards however, as the Command key is usually placed where the Alt key is on most keyboards (next to the Space bar).
When using a keyboard on the Xbox 360 console, pressing the Windows key performs the same action as the Guide button on the Xbox 360 controller or remote controls, opening the Xbox Guide in game play. Additionally, holding down the Windows key and pressing M opens a pop up conversation window over game play if an Instant Message conversation is in progress.