flash bios unknown

Recommended by Wim's BIOS...

I have been trying to update my bios because my primary slave is not being detected all the time only intermittently. My mother board is a P2-99 Asus and it used Award Modular Bios v4.51 PG and ACPI Revision 1009A. I tried to used flash, aflash, and pflash (all the flashes I could find and I keep getting the message rom bios unknown so I cannot update. When I bough the pc, I was not given any disks to uninstall the bios. Being 1999, is it possible that this bios 1009A is no longer available. Could you please think of a way I can get around this problem..I made inquiries in the internet regarding detection of hard disk. I was told to do a "reset configuration". Unfortunately my bios does not give me this option. All I can do is to reset the bios or setup which did nothing to solve the problem.. Would you by any chance have an idea how to solve this problem..thanks

Same board, same problem at this link:
http://www.wimsbios.com/phpBB2/viewtopic.php?t=877