Web portal software presents a GUI for installing and updating software applications on a computer. A method of using the GUI includes steps of: (a) specifying the configuration of an end user computer, (b) selecting on the GUI a software application program, (c) downloading a software package containing said selected software application program and arranged for the specified configuration, and (d) installing the software program by executing the software package. If the selected software package is not available for the specified configuration, step (c) is preceded by (e) the supplier creating a software package arranged for installing the software program on a computer having the specified configuration. The specified configuration may comprise an operating system type, a processor type, software application programs already installed on the end user computer, and/or a required dynamic link library, a registry entry, and a required parameter name in computer files.