It's not an environment variable, I'm actually trying to set a Windows Installer property for an installer that I'm calling from my Qt program, and this installer is actually quite sensitive to these extra double quotes.

It seems that the Qt code should attempt to parse the arguments and ignore spaces that are already escaped and enclosed within double quotes, rather than just indiscriminately check if the arg contains a space anywhere in it. And I'd rather not have to try to modify Qt source and I wish there was a way around it... cursed time deadlines