I ran across a file that had ".fax" as its extension, which was bogus, and wanted to know what it really was. Looking at the file in NotePad, it was just gibberish, and offered no clue to its real identify. Then I found TrIDNET, downloaded it and gave it the file to analyze. Poof, it was really a TIFF (Tagged Image File Format), an older graphics image format. I renamed the file with a ".tiff" extension and voila, it displayed just fine.