InWindows,OS/2, andDOS,.exe is thefilename extension for a file that is runnable as a nativeexecutablecomputer program.[1] Such a file is sometimes referred to anEXE – as one historical way to identify a file extension is without the dot prefix and capitalized.
Although the EXEfile format has a common lineage across related operating system (OS) versions, the format was enhanced over time. Some amount of backward compatibility was supported in later versions but earlier versions cannot run an EXE formatted for a newer version. Formats include:
DOS MZ executable
TheDOS MZ executable format is used byMS-DOS compatible operating systems. This format is 16-bit.
New Executable
TheNew Executable (NE) format was introduced with the multitaskingMS-DOS 4.0 and also used by 16-bitOS/2 and Windows. This format is 16-bit.
Linear Executable
TheLinear Executable (LE) format is mixed 16/32-bit and was introduced with OS/2 2.0.VxD drivers onWindows 3.x andWindows 9x also use this format. A 32-bit only version identified as LX was also introduced with OS/2 2.0 and runs on OS/2 2.0 and higher.[2]
Portable Executable
Introduced withWindows NT, thePortable Executable (PE) format is afat binary consisting of both a DOS and a Windows part. TheDOS stub is runnable on a DOS system but is ignored by Windows. The Microsoft C++ linker, by default, adds a small DOS program that prints the message: "This program cannot be run in DOS mode" and exits.[3][4][5] Windows ignores the DOS stub and executes the 32-bit Windows-specific portion.[3] With some linkers, it is possible to specify a custom DOS stub.[3][4][6] Indeed, there are a few dual programs, such asregedit inWindows 95[7] and old versions ofWinZIP self extractors. A 64-bit version, PE32+, was introduced with 64-bit versions of Windows. In most cases, code can be written to simply work as either a 32 or 64-bit PE file.[8] This format also includes a DOS stub.[6]
Other
There are other EXE formats, including but not limited toW3 (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 byPhar Lap extenders).[9]
^abEllermann, Frank (2014-01-22)."dostub.exe".Purl.net. Retrieved2014-01-24.
^"Using Registry Editor in Real Mode".Support.Microsoft. 2006-11-15. Archived fromthe original on 2014-01-15. Retrieved2014-01-10.Windows 95 includes a Registry Editor program (Regedit.exe) that runs in both the real-mode MS-DOS environment and in the protected-mode Windows environment. When you need to modify the registry without starting Windows 95, use Registry Editor in real mode. Note that the switches listed in this article only work in real-mode.
