File Extensions EXE File Format SUMMARY: The EXE executable (program) file format defined.   A file ending in ".EXE" usually means the file is an executable, or program file. This contains code that the computer follows in order to perform a particular task. A word processor, such as Microsoft Word, is an executable file; when started (double-clicked), the computer reads the file and executes the contained instructions to start up a word processing application. The same can be said for game executables, spreadsheet executables such as Microsoft Excel, music player executables such as Winamp, and so on. Executables can tell the computer to run virtually anything possible. This means that while most executables are useful for you to perform tasks, play games, access the Internet, etc., computer viruses may also be started by executables. When run, they could format your computer, randomly delete files, send spam e-mail to others, or whatever. While a program's filename (the part of the file before the period) SHOULD give an explanation of what running the executable will do (for example, WINWORD.EXE starts Microsoft Word and EXCEL.EXE starts Microsoft Excel), filenames can be named virtually anything. Thus, you should only start executable files that you trust. DO NOT just run any .EXE executable sent to you via electronic mail; it may contain a computer virus that can cause damange to your machine and possibly others'! Even if you are sent a file called WINWORD.EXE, that doesn't mean running it will actually start a copy of Microsoft Word.   Add: Del.icio.us | Digg | Furl | My Yahoo!   Discuss This Tip Print This Tip Get E-Mail When New Tips are Online Return to the File Extensions page.