A good start is probably to reset the CMOS on your computer. This will restore the configuration options stored by the computer to their factory defaults. Do this by holding down the
Delete key on the keyboard while you switch the computer on. (If you'd like a more detailed description of the whole malarky, have a look here.) Note that you must actually use the power switch! Using the reset button isn't enough.
Once you've reached the desktop following this, press the
F12 key and type:
Configure IDEDiscs 1 and press
Configure ADFSBuffers 0 and press
Configure FileSystem ADFS and press
Configure Drive 4 and press
Configure Boot and press
ADFS and press
Opt 4,2 and press
Return again and then re-start the computer.