20 Windows 7 Keyboard Shortcuts

Twenty Windows 7 Keyboard Shortcuts:

From Desktop
  Windows Key + Tab = Aero [press Tab to cycle between Windows]
  Windows Key + E = Windows Explorer is launched.
  Windows Key + R = Run Command is launched.
  Windows Key + F = Search (which is there in previous Windows versions too)
  Windows Key + X = Mobility Center
  Windows Key + L = Lock Computer (It is there from the earlier versions as well)
  Windows Key + U = Ease of Access
  Windows Key + P = Projector
  Windows Key + T = Cycle Super Taskbar Items
  Windows Key + S = OneNote Screen Clipping Tool [requires OneNote]
  Windows Key + M = Minimize All Windows
  Windows Key + D = Show/Hide Desktop
  Windows Key + Up = Maximize Current Window
  Windows Key + Down = Restore Down / Minimize Current Windows
  Windows Key + Left = Tile Current Window to the Left
  Windows Key + Right = Tile Current Windows to the Right [Continue pressing the Left and Right keys to rotate the window as well]

  Windows Key + # = Quicklaunch
  Windows Key + = = Magnifier

From Windows Explorer 
  Alt + Up = Go up one level
  Alt + Left/ Right = Back/ Forward