I am doing this tutorial https://www.metic.net/maya/HDRI/hdri.php and towards the end, the HDRI image was eliminated from the rendered scene by simply clicking on the R in the layer. This does not work the same way in version 7. I have messed with the overrides quite a bit but havent really been able to figure it out. I've been able to remove the nurbs plane and sphere in the center from the renders but not the HDRI sphere.

thanks for any help.