Can you clarify a bit please. What does 'when I get the XP loading' mean? Is this booting machine from XP install CD, and if so, what's the exact error message you get from it?
Do you need any special drivers for this machine/drive (eg, not a SCSI drive, or using a controller card or there is at least one mobo that although its a normal IDE controller connection, needs its own drivers for XP/2k to be able to recognise the drive)? Can supply these by pressing F6 when prompted during install.