Compaq 247320-003 - Deskpro 4000 - 5166 Model 2500/CDS Reference Manual page 21

Never restrict the airflow into the computer by blocking the
front vents or air intake. Do not place the keyboard, with the
keyboard feet down, directly against the front of the desktop
unit as this also restricts airflow.
Never use the desktop computer on its side (resembling a
"tower" configuration).
Keep the computer away from excessive moisture, direct
sunlight, and extremes of heat and cold. For information
about the recommended temperature and humidity ranges
for your computer, refer to Appendix B, "Specifications."
Keep liquids away from the computer and keyboard.
Never cover the ventilation slots on the monitor with any
type of material.
Turn off the computer before you do either of the following:
Wipe the exterior of the computer with a soft, damp
cloth as needed. Using cleaning products may discolor
or damage the finish.
Occasionally clean the air vents on the front and back
of the computer. Lint and other foreign matter can
block the vents and limit the airflow.
To properly turn off your computer, click Shut Down... on the
Start menu. The computer will automatically shut down.
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