These forums fill with folk that used externals to "store" content without backup.

And yes, Windows or an app can cause this. For EXAMPLE> WMP has it's feature to move and rename content automatically which creates no end of fuss. Apple, I think has turned that off in later versions.

There are other reasons such as the externals are in that old FAT32 format which is old and unreliable.

But still there's the one thing. Storage is not what these are. It's a shame this lesson is often learned but never taught.