You're probably aware that most files have an extension such as TXT or EXE after the file name, even though these are not always displayed in Windows. File extensions are how Windows knows what to do ...

A file extension is a suffix that is added to the end of a file name after a dot. It is usually two to four letters long. File extensions help Windows and other operating systems to know the standard ...

A bug in Lion means Apple's popular TextEdit utility may append the TXT extension to files regardless of their original file types. Topher, an avid Mac user for the past 15 years, has been a ...