I would suggest only one drive connected. The working one. It is a Maxtor? If yes then first off run MaxBlast from the above link to install the drive. MaxBlast is a download that you will create a bootable floppy from. After that try to install XP by booting the CD.

Clicking would indicate some problem with the mechanical arms that read the discs. This happens with age. Like creaking bones. The PowerMax is also a download that you create a bootable floppy from. It is a diagnostic for Maxtor drives.

If your BIOS sees the hard drive but the XP CD cannot this would point to the drive as the problem. If your BIOS is not detecting the drive then the problem is on the board or in the connections.