If not the jumper problem suggested in the previous reply, then you probably
have reached a BIOS limit. If the PC/motherboard is more than a few of
years old, it may old be able to handle disks up to 32Gig (approximately).
Look for a BIOS update to solve the problem. If no update is available, get
an ATA/100 PCI adapter card, which has its own BIOS ith a higher limit. I
used one of those on a 1998-vintage Gateway computer to install larger
disks.
Note also that there is another BIOS limit about 128Gig. So be sure to get
an adapter that goes higher.
Finanlly, there is an XP limit at 128Gig. To go past it you need SP-1 and
48-bit LBA enabled.