Or is there another switch to stop it?
Yes, there is. I see I forgot to document this, I will do it in the next release. There is an additional installer commandline parameter:
/TASKS="comma separated list of task names"
With this you can specify the additional tasks to be performed. There are 4 task names to choose from: "Associate", "CreateDesktopIcon", "SelectScreenSaver", and "CreateScheduledTask". The default setting is:
In your case you will probably want to use: