1. Win+B to select the first icon in the Notification Area.
2. Win+D to show the desktop, or restore hidden programs when pressed a second time.
    3. Win+E to open Windows Explorer.
    4. Win+F to open Windows Search.
    5. Win+CTRL+F to open Search for Computers. Requires Active Directory
Domain Services.
    6. Win+CTRL+ALT+↵ Enter
toggles full screen in Internet Explorer. This shortcut has been  discontinued, replaced by F11.[when?
    7. Win+F1 to open Windows Help.
    8. Win+L to lock the desktop or switch users.
    9. Win+M to minimize all windows.
    10 .Win+⇧ Shift+M to
restore windows that were minimized with ⊞ Win+M.
    11 .Win+R to open the Run dialog.
    12 .Win+U to run Utility Manager, replaced by Ease of Access in
later versions of Windows
      13. Win+Pause
or ⊞ Win+Break to open System Properties.
    
14. ctrl  +  + windows  resolution zoom up 
14. ctrl 
+  - windows  resolution zoom
down 
NOTE :-   Windows XP
Media Center Edition adds ⊞ Win+Alt+↵ Enter, which starts Windows Media Center interface.