[KaterinaNJq]

While in the BIOS, I'd recommend that you ensure that it is recognizing the drive correctly on each startup. The easiest way to ensure this is to reset your BIOS default settings. While on the BIOS screen, look for an indication either along the top or bottom designated by one of the function keys (I believe it used to be F10 to restore defaults). Be sure to save your changes and exit.

I did all that before I installed the new HD.

Second, physically check all cabling. A loose or in some cases failing IDE cable (assuming it is an IDE and not SATA connection) will produce these errors. Power everything completely down, remove the side of the case to give access to the drives and start with reseating the cable both at the drive end and the controller (where they plug into the motherboard) ends. Ultimately, if you were to pick up (or could somehow borrow) a different IDE cable to test for a short time it may also call out a failed or failing cable as well.

Other than trying a new cable I had done everything else while I was inside the box.

Third, we can't overlook the possibility of a failed drive itself. Formatting and/or recovering the drive will most likely not correct an error of this type.

That's why I initially saved a bunch of time and installed a brand spanking new HD right off the bat. The problem resurfaced after I changed the old HD to a slave and stuck it back in the box. When I removed the old drive for the second time it booted up just fine. The problem redeveloped after she got it home.