Can an external hard drive switch it's file format on it's own?

A few years ago I lost an external hard drive which had my photos and videos on it(not backed up anywhere so it's kind of important for me) and a couple of weeks ago I found one which could be it(also I don't remember what it looked like so there's a chance the one I found has nothing to do with the... show more A few years ago I lost an external hard drive which had my photos and videos on it(not backed up anywhere so it's kind of important for me) and a couple of weeks ago I found one which could be it(also I don't remember what it looked like so there's a chance the one I found has nothing to do with the lost one), but when I tried to browse the files on it, a message popped up saying "this hard drive needs to be formatted before use". After some investigation I found out it has an ext4 file system which is used in linux, and is unreadable in windows.
Could it be that the hard drive somehow managed to switch it's file system on it's own? Or maybe I didn't actually find the lost hard drive?
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