invalid file format on external 300gig

[kezm]

ok lent this drive to my m8 was working fine it comes back and now when you connect it says invalid file format is there any way to repair this as it has 260 gig of files on it and any idea what has happened

[PhilEnfield]

He didn't convert it to FAT 32 by any chance ? .... assuming you're on NTFS or vice versa ?

To check ..... right click on drive in My Computer and select Properties.