Windows executable (.EXE) file compressed using some form of compression and renamed from ".exe" to ".ex_;" often found on software installation CDs, where the installer must first rename the file and decompress it before execution; useful for decreasing the size of an EXE file when packaging installers onto external media or within downloadable archives.

EX_ files are commonly created using Makecab, a file compression utility included with Windows. Here is example syntax for creating the file program.ex_ from the file program.exe: makecab program.exe EX_ file created with Makecab can be decompressed back to their original form using the expand.exe program included with Windows. It uses the following syntax: expand program.ex_ program.exe