Make Use Of Your Windows Key

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

ref: http://www.tunexp.com/tips/customize_your_computer/make_use_of_your_windows_key/