Hello, lacie 1 tb external hard drive was accidentally reformatted to8gb now cannot access previous data
More aboutexternal hard drive
You'll have to use some kind of recovery software. You could pay a tech store to do it for you, but it'd be expensive. If you haven't done much to the drive since then (don't do ANYTHING), it should work.
First, stop writing to the drive. Download 'RECUVA' and see whether that helps.