Some useful shortcut key in Windows 7 and 8

1. To open, hide or show run dialog Press Windows key + R together.

2. To select any of the taksbar pinned program Press [Window + program position in taskbar] together.
    Say your Firefox is in 4th position from the left then press Window key + 4. If the program is running and
    in minimized state or not an active window then pressing this buttons will make it active window or
   maximized if it is minimized.

3. To open search window on a particular folder. Select the folder from the explorer and press
    Windows key + F.

4. To minimize all window press Window key + D.

5. I hope you know about the second screen window, it is used if you want to extend your monitor to a
    projector,  or make a duplicate screen to another monitor etc. To open the second screen window, press
    Window key + P.

6. To minimize all screen Press Window key + M.

7. To open the explorer window press Window key + E.

8. To open the start menu press Window key, or press Control key + Escape key.