Files with the .EX_ extension contain executable Windows EXE files in compressed form, with a changed extension. To execute the file, it must first be decompressed and its name must be changed. The files are used to decrease the size of software installers, such as those placed on CD drives or those that must be downloaded from the Internet.

EX_ files are often created with the use of a file compression tool – or using the makecab Windows system command, which assumes the file name as a parameter, creating a compressed file with the same name and a changed extension. To decompress the file, one would also use a Windows tool – namely the expand command, which, in turn, assumes the names of the to-be decompressed file and target decompression file as parameters.