You need to provide information about your computer, this includes is it
a laptop or desktop, is it a custom build or brand name such as Dell or HP
and if it is provide the model name or series number.
You may have damaged the OS beyond repair and so a format and fresh install
may be the only solution, also consider the possibility that the HDD may
have issues, any earlier problems such as clicking or slow access times?
If you have data on the drive that you would like to retrieve then booting
from puppy linux is an option
http://www.geekstogo...over-your-data/I have tried booting from disk and have configured it so it does boot from disk but it didn't work
Please confirm that when you configured the boot sequence in the BIOS that it was set to 1st CD/DVD drive 2nd HDD and that you saved the settings (F10) and then pressed Y to accept the changes, this will also tell us if the BIOS is detecting the HDD.