About a week ago we rebooted the old computer my kids use and got a divide overflow error. Apparently it was something to do with the hard drive. There had been problems with that drive before, so I had another hard drive (6.4 gig western digital)that we were not using that is newer and I knew was working perfectly in my old 486-100, so I installed it. This computer is a Pentium 133. Then the problems really started. The bios could not pick it up in the auto detect IDE drives, but if I set it to auto in the CMOS setup instead of user specified, it found it and correctly reported the size. But after booting up, I got a hard disk failure (80) message. So I inserted a boot disk and got it up from the floppy drive. Used the EZ Drive floppy from the drive manufacturer. It found both the hard drive and the CDROM drive, formatted and partitioned the hard drive. I also used the EZ Bios since it reported that my actual bios could not support a drive that size. Rebooted again and got the same hard disk error. The drive appears to be working, but the computer cannot see it. DOS doesnt see it. If I take it out and put it back in the 486..it works fine. Suggestions?