jpeg files dont open or display like jpg files, are they the same? I noticed that when I rename jpeg top jpg it is able to open, I am not sure if it is the cross platform from Mac to PC or if it has something to do with digital camera format.
Internally, you'll find that a jpeg file and a jpg file are one and the same. Both file types have a header that includes JFIF to identify the type of file.
You don't specify which OS you're using that has this problem, but if it is a Windows machine, your defaults are set in such a way as to have no application assigned with which to open the jpeg file type.
The specific steps are dependent on the version of the operating system. The steps involved for Windows 10 are very different from those for Windows 7, but can easily be located using the search terms "set default applications windows X" and finding a tutorial which appeals to you.
You can also right click on the filename and use "open with" then select the entry "use default program" from the context menu.
I figured it was a operating system difference, I have jpeg files associated with photoshop and they open fine, just when I use them in my slideshow program in the file list view, those jpegs have extra unidentified characters at the end of the file name, not to mention they dont show. I have to go back and rename them to .jpg to make them show and then the actual name is corrected with out me renaming the full name of the file just the extension.