Yesterday I needed to copy some data from my girlfriend's laptop to mine. To do so I just copied my whole data from my external hard drive to my PC and used the hard drive for data exchange. After copying the data, I made a low-level format and copied my whole stuff back on my external hard drive.
But, now neither Ubuntu nor Windows can detect the hard drive and I can't format it again because I removed the data from my laptop. Does it mean that the boot sector is corrupted?
If so, what can I do to fix that?