As you tried two different drives it sounds like your hard drive cable or
power is not making proper connection.  If your BIOS isn't detecting the
drive it means it does see it.  I would use a different connector from your
power supply and install a new drive cable to see if that allows the BIOS to
detect your drive.  You could also try the second IDE connector on your
motherboard.  If that solves the problem I would check the Disk with Fdisk
and possibly even format again this drive to make sure you have a clean basis
for starting a new OS install.

Regards,
Mike Scott

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