Each HDD mfgr has a utiltity to do two things:
Test the HDD for drive errors.
Zero out the HDD in part or full.
Newer HDD's cannot be low level formatted. Factory job. They can be made ready for OS in factory formatted state by zeroing out the drive.
Download the utility to C and .exe into a formatted floppy.
Boot to the floppy and run the utility. Quick or Advanced for full diagnosis.
I ran both Quick and Advanced no errors. Since new HDD was installed I ran zero entire drive. Failed near completion. Ran Quick and found error with recommendation for another reformat to zero. Chose by sector and it failed. Important Point: Copy failure screen by hand including failure code.
Went to HDD mfg and by ser no found drive warranty expiration date Jan 05. Filed RMA. Critical piece of info was failure code. Within minutes RMA number. Mfr picky on packaging. I used black foam.
12 days later "Serviciable Used Part" arrived.
Shipped 60G, UDMA 100 got back 80G UDMA 100