This Microsoft tool is used by MAKEMSI to "compile" files (see the "compile" command).
This tools is not provided with MAKEMSI (due to Microsoft's licencing requirements). It exists on Windows 2000 and XP boxes with base installs. For other operating systems you will need to download the "CAB SDK" from Microsoft (http://support.microsoft.com/kb/310618) as it contains the tool, you must also ensure that MAKEMSI can "find" it by making sure the installation directory is included in the list defined in the "PATH" environment variable.
See the "MAKECAB.EXE Issues" section for some details of MAKECAB.EXE bugs/features.
You can use the "COMPILE_MAKECAB_EXE" macro to specify the version that makemsi should use by default MAKEMSI will search tha "path".
Cabinet Maker - Lossless Data Compression Tool MAKECAB [/V[n]] [/D var=value ...] [/L dir] source [destination] MAKECAB [/V[n]] [/D var=value ...] /F directive_file [...] source File to compress. destination File name to give compressed file. If omitted, the last character of the source file name is replaced with an underscore (_) and used as the destination. /F directives A file with MakeCAB directives (may be repeated). Refer to Microsoft Cabinet SDK for information on directive_file. /D var=value Defines variable with specified value. /L dir Location to place destination (default is current directory). /V[n] Verbosity level (1..3).