I am not sure, if your package reports that the version of Gear Wizard model is 4.0 instead 7.5, maybe you can try the latest version of NX7515. You can download upgrade package of 7515 from below link, here:
I do not have NX7515 installed in my machine, so I cannot confirm that with you. Anyway, whatever the Gear Wizard version is, if you can use it, just use it, I do not think version number is a critical issue for you.