Windows in general:
Windows + E: Open Windows explorer
Windows + R: Open Run dialog
Windows + D: Minimize/restore all (show desktop)
Ctrl + Shift + Esc: Open process explorer
Explorer:
F10 or Alt: Show menu bar
F4: Move focus to adress bar
F6: Move focus to next pane
Alt + Space: Open the system menu for the windod (minimize, maximize, etc)
Ctrl + e or F3: Move focus to search bar
Shift + F10: Open right click menu for current item
Ctrl + w: Close the current window
F11: Full screen mode
Shift + F11: Exit full screen mode
Windows 7:
Windows + 1 to 9: Pinned applications
Windows + Left: Dock current window left
Windows + Right: Dock current window right
Windows + Up: Maximize current window
Windows + Down: Restore current window
Windows + Shift + Left: Move to screen to the left
Windows + Shift + Right: Move to screen to the right