Does this work on other windows systems such as XP?
This could be anything from a defective HDD, defective Lacie enclosure, Odd format on the Hard disk, bad or confused USB port on your PC etc.
Check it is seen in device manager
Check it is seen in disk management
Check it is formatted in either NTFS or FAT32 in disk management
This are the best suggestions i can think of with such little information.
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