IQON COMPUTER - Serial No. 237733066?

When I turn on the base unit of my Iqon Computer,
I get a message:

Disc error - please any key to enter
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If I press any key, the same message appears!

Now, the only way I can start my computer is

Turn on and press F12 continously on startup

Select Hard Drive from Boot up menu

Select Hitachi (have choice of Sony or Hitachi)

Then computer will start up

The computer was NOT supplied with a Disc as
I understand the system should always boot up
from the hard drive.

How can I change the boot up programme so
that the system will always look for the HDD
to start up from ?