Open all subfolders of selected folder
Num Lock+Asterisk (*) on numeric keypad
Display contents of the selected folder
Num Lock+Plus sign (+) on numeric keypad
Collapse the selected folder
Num Lock+Minus sign (-) on numeric keypad
Collapse folder (if expanded), or select parent folder (if not)
Left arrow
Display folder's contents (if collapsed ), or select first subfolder (if not)
Right arrow
View previous folder
Alt+Left arrow
View next folder
Alt+Right arrow