For Microsoft Windows, OS/2, and DOS, .exe is the filename extension that denotes a file as being executable – a computer program – containing an entry point.

[1] In addition to being executable (adjective) such a file is often called an executable (noun) which is sometimes abbreviated as EXE.

An operating system cannot use an EXE file unless it is formatted for it.

Note that some formats support multiple operating systems.

There are other EXE formats, including but not limited to W3 (a collection of LE files, only used in WIN386.EXE), W4 (a compressed collection of LE files, only used in VMM32.VXD), DL, MP, P2, P3 (last three used by Phar Lap extenders).