This had worked for me until yesterday’s Mac update, when my Web Driver stopped working and again found I couldn’t update from the CUDA module in System Preferences. I had tried deleting everything and reinstalling the Web Driver, but kept being told it wasn’t compatible.
I’ve tried it today and it’s now working. I suspect my issue was that I hadn’t completely deleted all the files (Nvidia seem to make things quite difficult, including some needless questions for registering for this forum.)
I followed the directions in the OP, and like many here could not find the following:
However, within the folders I could access there seemed to be shortcuts to other folders, so this time I went into those folders individually and deleted all the files within, as I suspect I was only deleting the shortcut links before.
After a restart I then downloaded the WebDriver-3188.8.131.52.20.109.pkg from here: https://images.nvidia.com/mac/pkg/378/WebDriver-3184.108.40.206.20.109.pkg and it installed without issue.
After a restart I then downloaded the CUDA Support Driver linked in the OP (http://www.nvidia.com/object/macosx-cuda-9.0.222-driver.html) which again installed without any issues this time.
I’ve restarted and everything seems to be working OK and the fans on my Mac are no longer deafening :-)
I just wanted to register to thank hkunkun and the other posters for their help and let other people who are as technically inept as me how I managed to get it working.