I have some jpg files on an old hard drive, and it appears they were corrupted somehow. When I try to open them it says it's an invalid file type in Windows. I first attempted a couple of repair programs, but they both said it's not a valid jpg file. I then attempted to use Gimp which gave me the error:
Not a JPEG file: starts with 0x8b 0x80
I then checked it in terminal, and it said the file type was "data file," not an image file. I'm guessing these pictures are lost forever, but wanted to throw it out there in the event someone else has seen this and been able to fix it.