Primary hard disk drive 0 not found

Hi, my father has a DELL Optiplex Gx240 running Windows XP Pro. Recently he had a power failure and lost his System Disk. Fortunately his data was into another partition on that drive and there also was a Ghost image of his installation. Since I could not recover his C: (system) drive, I got a new Western Digital EIDE 250 Gb. Using partition magic on my computer, I partitioned the new drive in two different partitions. One, the Primary DOS NTS formatted of 30 Gb which I reserved for the system and and a second NTFS for his data with approx 215 Gb. From Windows Explorer on my computer I could see the new drive (connected through USB) and both partitions. I could copy the Ghost image (Symantec ver 8) to the second partition and move files around on both partitions. The hard drive was tested with WD diagnostic soft and went through Ok.

I then re-installe de new drive into my dad's computer and booted from a DOS 6.22 diskette. I noticed a message saying that "Primary hard disk drive 0 not found" and "Primary hard disk drive 1 not found" so I went into the BIOS to make sure the drive was active. It was and was properly identified by the BIOS.

I then completed the Boot process and ran the Ghost program from a diskette. Ghost could see the hard disk and I could de-ghost the image I had copied on the second partition to the first partition.

When I rebooted, The computer without a diskette, I stil had the "Primary hard disk drive 0 not found" message.

I can stille see the drive in my dad's computer BIOS, and I can see the de-ghosted files in Windows Explorer on my computer.

So everything is there but the Optiplex does not seem to be aware of it. Since the waranty is over, is there any suggestion from someone of the next step I can take to solve this issue.

By the way, I updated my dad's computer from Phoenix BIOS A01 to A05.

Completely at a loss...