Dell OptiPlex GX1p User Manual page 89

Chassis Intrusion: Dell™ OptiPlex™ GX1p
If the Chassis Intrusion option is set to Enabled in the System Setup program and the system cover is removed, the following message is displayed during the boot
routine at system start-up:
Alert! Cover was previously removed.
To clear this message and allow future intrusions to be detected, make sure that the computer cover is closed, and then enter the System Setup program during the
system's POST, and press any key to reset the Chassis Intrusion from Detected to Enabled.
The option can also be set to Disabled to turn off the chassis intrusion feature, or Enabled-Silent, to prevent the alert message from being displayed at system start-
up.