Dell Dimension XPS 50 Reference Manual page 136

B-2 Dell Dimension XPS Txxx and Txxxr Systems Reference and Troubleshooting Guide
Table B-1 lists the keys you use to view or change information on the system setup
screens and to exit the program.
,  
Displays help information.
Returns to the parent menu; from a parent menu, exits with-
out saving changes.
Moves the cursor up or down to select an item.
or
Moves the cursor to the previous or next menu option.
or
Increases or decreases the current value in the selected field
or cycles through settings for the selected option.
or
Selects the submenu for the current option (if there is one)
or, on the Exit menu, performs the current command. For
System Time and System Date, pressing <Enter> moves
the cursor to the next field.
Reverts all settings to the initial defaults.
Saves changes and exits the program.
For System Time and System Date, moves the cursor to
or
the next or previous field.