Hi Peter,
You can use the COMMAND$ keyword to return the command line used to start the program. If you double click on a .prg file to launch HTBasic, it will return the path and name of the HTBwin.exe run followed by the path to the double clicked program file. This should give you what you need.
As a side note though, any driver that is found at the same location as the HTBwin.exe file, will be found when trying to load it, no matter what the MSI is set to.
Hope this helps,
Pat
