Windows 7 shortkeys with windows/logo button

Win + Tab : Flow view to switch between open windows.

Win + E : Open Computer in a new window.
Win + D : Minimizes all open windows on all monitors. Pressing it again restores the previous state.

Win + L : Lock computer.

Win + M : Minimizes all open windows on current monitor.

Win + Shift + M : Restore previously minimized windows on current monitor.

Win + R : Open Run window.

Win + X : Open mobility center (only on laptops)

Win + Space : Preview desktop, make all windows transparent.

Win + Up : Maximizes active window.

Win + Down : Minimizes active window; restore first if maximized.