|Sorry for assuming the worst, which is usually the case. Your plea indicated, to me at least, panic. |
Testdisk can repair partitions with faulty file systems.
If all that resides on that external are backups then I suggest you run a hard drive fitness test on it and if it comes back OK delete the partition and start over.
I don't think Lacie has their own brand of hard drive. You should be able to use the Hitachi test on whatever is inside the enclosure.
In Disk Management right click on the listing for the external at the far left. Choose properties> policies. Is write caching enabled?