During the POST, is the hard disk recognised? I suspect that it may not be indicating that perhaps its failed. However, first check that all connections are in place and that the data connection is round the right way on both the HHD and the mobo. Boot using an alternative media and see if you can read anything from the hard disk (i.e. from a bootable floppy at the a:\ prompt try typing c:\ and see what happens then report back.