Lacie hard drive not recognized is one issue which bothers the Mac users most. It is mainly caused by some severe corruption issues. There are several reasons which can cause Lacie drive corruption at any point of time such as abrupt system termination, damaged file system, header node corruption, power surge, etc. In such situation all the data store on the Lacie external drive will become ultimately inaccessible. However in order to fix Lacie hard drive not recognized issue you should check weather if your drive is connected properly or not. If there is any problem with the hard drive connection then reconnect it properly. It would be sensible to use only the certified cables to connect the external Lacie hard drive. However if you are still facing the same issue then you will have to format the corrupted Lacie drive in order to fix Lacie hard drive not recognized issue. Once the issue get fixed completely then you can use the backup files in order to restore your formatted data but if there is no backup available then directly look for Mac Data Recovery Software and get back all your lost files back and fix Lacie hard drive not recognized issue.