James just bought a 3TB hard drive, But Windows XP only sees less than a TB. Leo says that's not surprising. The bios of the computer may not see all the hard drive, but the OS is so old that it may not see it all either. For 3TB, he would need GUID. He can partition the drive into smaller chunks, though. He'll need a disk manager to do it. The XP Disk Manager should be able to handle it.