Dell OptiPlex 790 (Early 2011) - Manual (Page 86)

Memory tests terminated by keystroke
Description A keystroke interrupted the memory test.
No boot device available
Description The computer cannot find the floppy disk or hard drive.
No boot sector on hard-disk drive
Description The computer configuration information in System Setup may be
incorrect.
No timer tick interrupt
Description A chip on the system board might be malfunctioning.
Non-system disk or disk error
Description The floppy disk in drive A does not have a bootable operating system
installed on it. Either replace the floppy disk with one that has a bootable
operating system, or remove the floppy disk from drive A and restart the
computer.
Not a boot diskette
Description The operating system is trying to boot to a floppy disk that does not have a
bootable operating system installed on it. Insert a bootable floppy disk.
Plug and play configuration error
Description The computer encountered a problem while trying to configure one or
more cards.
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