Dell PRECISION 530 - Manual (Page 131)

Removing and Installing Parts 131
NOTE: If enabled, the Chassis Intrusion option will cause the following
message to be displayed at the next system start-up:
ALERT! Cover was previously removed.
10 Enter system setup and enter the current time and date. Then exit
system setup and save the information.
11 Turn off your computer and disconnect it from its electrical outlet.
Leave the computer off for at least 10 minutes.
12 Reconnect the computer to its electrical outlet and turn it on.
13 Enter system setup , and check the date and time.
14 If the time and date are still incorrect, contact Dell for technical
assistance.