Look on the drives and find the manufacturer, go to <A HREF="http://www.bootdisk.com" target="_new">http://www.bootdisk.com</A> in the Utilities section toward the middle of the page, in the Hardrive section, locate the manufacturers Diagnostic disk creator executable file, download it to My Documents, then find the file you downloaded, put a blank formatted 3 1/2" floppy in your floppy drive, and double click the file you downloaded, it will create a diagnostic bootdisk for your hardrives, put the hardrive in the machine, put the disk you created in the floppy drive and start up the computer, making sure the CMOS is set to boot from the floppy drive, then in the diagnostic program find, Disk pack write(Low Level Format) ,and run the program with a 28Gig it will probably take an hour or more to complete, after it completes the drive will be just like it came from the factory. Do each drive independently and make sure the hardrive is the only hardrive in the machine, preferably as the master of the primary IDE, that way you can't mess anything else up. When you install your operating system then you'll partition and format, through your OP/SYS install disk.
Details, Details, Its all in the Details, If you need help, Don't leave out the Details.