Tring to back up pc to elements 1 tb external hd

FAT32 is a type of disk management, but this is not used for hard disks normally. i already heard that several external hard disk manufacturers by default format their hard drives to FAT32.
you should connect the hard drive, wait until it's recognised by windows and then simply format it to the NTFS-format.
you can do this by right-clicking the hard disk and choosing 'format' from the drop-down menu. be sure to make copies of all files you keep on the disk, because all files will be lost during the format.

Fat32 simply means that your hard drive can only read files up to 4GB, format your external harddrive using file system NTFS then try to back up all your files again. Hope it helps you...