Move to the next option or option group.
Move to the previous option or option group.
Ctrl+Tab or Ctrl+Page Down
Switch to the next tab in a dialog box.
Ctrl+Shift+Tab or Ctrl+Page Up
Switch to the previous tab in a dialog box.
Move between options in an open drop-down list, or between options in a group of options.
Perform the action for the selected button, or select or clear the selected check box.
First letter of an option
Open the list if it is closed and in a drop-down list, move to that option in the list.
Alt+ the underlined letter in an option
Select an option, or select or clear a check box.
Open the selected drop-down list.
Perform the action for the default command button ...