Vista, Windows 7, Windows 8.1 Keyboard Shortcuts

Managing Windows
Alt+F4	Close the active window
Alt+Tab	Switch to previous active window
Alt+Esc	Cycle through all open windows
Win+T	Cycle through applications on taskbar (showing its live preview)
Win+M	Minimize all open windows
Win+Shift+M	Undo all window minimization
Win+D	Toggle showing the desktop

Starting Programs
Win+1	Open the first program on your Quick Launch bar
Win+2	Open the second program on your Quick Launch bar
Win+n	Open the nth program on your Quick Launch bar
Win+U	Open the ease of access center
Win+F	Open the search window
Win+E	Open Explorer
Win+R	Open the Run window
Win+B	Move focus to notification tray (the right-most portion of the taskbar)
Win+Pause	Open the System Properties portion from the Control Panel
Ctrl+Shift+Esc	Open Windows Task Manager