HP Vectra VL800 Technical Reference Manual page 137

The following table summarizes the most significant of the problems that
can be reported.
Message
Operating system not found
Missing operating system
Resource Allocation Conflict -PCI device
0079 on system board
Video Plug and Play interrupted or
failed. Re-enable in Setup and try again
System CMOS checksum bad - run
Setup
No message, system "hangs"
Other
Explanation or Suggestions for Corrective Action
Check whether the disk, HDD, FDD or CD-ROM disk drive is
connected.
If it is connected, check that it is detected by POST.
Check that your boot device is enabled on the Setup Security
menu.
If the problem persists, check that the boot device contains the
operating system.
If you have configured HDD user parameters, check that they are
correct. Otherwise, use HDD type "Auto" parameters.
Clear CMOS.
You may have powered your computer Off/On too quickly and the
computer turned off Video plug and play as a protection.
CMOS contents have changed between 2 power-on sessions. Run
Setup for configuration.
Check that the main memory modules are correctly set in their
sockets.
An error message may be displayed and the computer may "hang"
for 20 seconds and then beep. The POST is probably checking for a
mass storage device which it cannot find and the computer is in
Time-out Mode. After Time-out, run Setup to check the
configuration.
7 Tests and Error Messages
Error Message Summary
137