If FDISK can not see the disks then the BIOS has a problem with the DISKS or the DISKS are not set up in the BIOS or they have some kind of software on them designed to hide the partitions or an overlay program.
Having a Post detect a hard drive and actually having it set up in the BIOS are 2 entirely different things. A post can often see a CDROM also, but older hard motherboards could not boot from them until after the hard drive had the appropriate device driver installed. What happens when you go into the BIOS and try to detect it in the BIOS? This is not the option for the BOOT order. This is the option to set up the DRIVE in the BIOS. To address a hard drive it must be set up in the BIOS. If you have a setting for AUTO change it from auto to manual and then beck and see if it can read what kind of drive it is.
Here is a suggestion you might try. First see who manufactured the hard drives. Then go to their website on the Internet and look for their hard drive utilities.
One question I would ask at this point is what is the capacity of the Hard Drive (Size in Gigahertz)and what is the limit for the capacity of hard drives for your motherboard and BIOS? Is this a really large Disk or is it an older smaller disk?
Sometimes it is prudent to try other methods to attack a problem. A Linux REDHAT install disk can see the partitions and reformat them. The manufacturer of the hard drive may have some software to detect, diagnose, and have some remedies like a low-level format. I know there are some utilities like Partition Magic V6 or maybe V5 that might work also.
If you have access to an XP install disk, you can go through a New Install and delete the existing partitions and just turn your computer off. An XP install disk should be able to read NT or Win2k or XP partitions. An XP install disk can also create and format fat32 PARTITIONS. Most likely you have some friend or know someone that has an XP install disk.
Sometimes a hard disk has had some overlay program on it that has to be removed. These programs are used to use a hard disk that is too large for your BIOS. Usually the drive manufacturer has them for a download as a utility or hard drive installation software. They can also usually be used to remove or undo existing overlay programs. They usually have drive diagnostic software with them.
This might work:
These are some of things you might try.
If you do not like my post feel free to point out your opinion or my errors.