Dell OptiPlex GX1 Reference And Installation Manual page 111

or
Strike the F1 key to continue,
F2 to run the setup utility
To determine whether the battery needs replacing, reenter the time and date through
the System Setup program (not through the MS-DOS time and date commands) and
exit the program properly to save the information (see Chapter 2, "Using the System
Setup Program," for instructions). Turn off your system and disconnect it from AC
power for a few hours; then reconnect and turn on your system. Enter the System
Setup program. If the date and time are not correct in the System Setup program,
replace your battery.
You can operate your system without a battery; however, without a battery, the sys-
tem configuration information is erased if the system is turned off or unplugged from
AC power. In this case, you must enter the System Setup program and reset the con-
figuration options.
Use the following procedure to replace the system battery with another CR2032 coin-
cell battery:
If the settings are lost while you are replacing the battery, refer to your written or
printed copy of the system configuration information to restore the correct set-
tings. See Chapter 2, "Using the System Setup Program," for instructions.
Installing System Board Options 6-15