Dell OptiPlex E1 - Manual (Page 22)

malfunctioning. Indicates a fatal error.
Unexpected interrupt in
protected mode
Keyboard/mouse controller
malfunctioning, or one or more DIMMs
improperly seated. Indicates a fatal
error. Improperly seated DIMMs or faulty
keyboard/mouse controller chip
(defective system board).
Write fault
Write fault on selected drive
MS-DOS cannot write to diskette or
hard-disk drive. Faulty diskette or hard-disk drive.