IExpress is a Microsoft utility bundled with various editions of Windows operating systems (32-bit and 64-bit): Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, and Windows 7. It was also included as part of all Internet Explorer Administration Kit releases 4, 5 and 6, and was part of all installations of Internet Explorer 6.
IEXPRESS.EXE is used to create a single self-extracting package from a set of files. Such packages can be used to install applications, executables, drivers, other system components, or setup bootstrappers.

IExpress (IEXPRESS.EXE) can be used for distributing self-contained installation packages (INF-based setup executables) to multiple local or remote Windows computers. It creates a self-extracting executable (.EXE) or a compressed Cabinet (.CAB) file using either the provided front end interface (IExpress Wizard), or a custom Self Extraction Directive (SED) file. SED files can be modified with any plain text/ASCII editor, like Notepad. All self-extracting files created by IExpress use CAB compression algorithms, are compressed using the MakeCab (MAKECAB.EXE) tool, and are extracted using the WExtract (WEXTRACT.EXE) tool.