MS Windows Installer 2.0 Engine :

Dcat's programs are installed by the Install Shield installation program which uses Microsoft's Windows Installer version 2.0 engine. The MSI 2.0 engine is a freeware program provided by Microsoft and may be freely redistributed.

There are two available MSI files, one is for Windows 9x & ME and the other is for NT/2000/XP/2003. Windows NT4 requires Service Pack 6 or higher. Windows XP/2003 ships with the MSI 2.0 already installed so Package B could used instead of Package A.

Package A which includes both versions of the MSI engine, will install the MSI engine if required otherwise the MSI engine may be downloaded and installed. Package B or C then can be used.