i am working on an old computer i had in storage. i noticed that when it went through the POST it said the hard drive was not functioning properly and needed to be replaced. it seemed to be working fine but i figured i would replace the hard drive anyway. i bought an 80 gig off of newegg. i got it and installed the drive, but BIOS wouldn't recognize the hard drive, i returned the drive and got a new one. i installed the new one and everything seemed to be fine. windows install was working fine untill it rebooted. then all of a sudden the hard drive was gone again. i hooked it up to my working desktop and had no problems using it and reformating it there. hooked it back up to the other comp and BIOS woudln't recognize the hard drive. why is it not recognizing the hard drive? is it too big for the mobo? or is there issues with the mobo connector?