OpenG has a web site
here. To quote "OpenG is an organized community committed to the development and use of open source LabVIEW tools, applications, frameworks, and documentation.". Their Builder is not an alternative to having your own copy of NI's app builder. It is an enhancement to an existing installation of the app builder. In your case where you need app builder 7.0 or lower to create an exe for win98, the OpenG Builder will not help.