Select "remove driver" and run the uninstall.
You have to uninstall the new driver from the driver dialog that comes up from Device Manager. After about 5 tries using different methods, here's what worked, make sure you have a USB mouse handy because you're going to need it. I ran it in that order and it didn't work, the Synaptics driver update never shows up in the list.
I have had many Dell laptops, and sold many to customers, but that is about to end if this is the way Dell is going to conduct business. What is so hard to understand about that? I tried to bring this to the attention of Dell support, but it appears they do not want to hear it, since I am not allowed to contact them by email or chat and the phone line is just useless. I just spent over an hour fooling around trying to get my functionality back to where it was. I think Microsoft, Dell, Synaptics, whoever is responsible for this bad decision should re-visit it. The whole idea of forcing Windows updates on Windows 10 is wrong, and the idea of changing a driver that changes desired functionality is a huge mistake.
I solved it by uninstalling the driver then reinstalling an old version, but I am concerned that in future Windows update is going to trash this again. It changed gestures to use some new Windows 10 features that I DO NOT WANT TO USE and disabled the gestures I had been using since I got this laptop 9 months ago.
12 trashed my Touchpad settings with the install of a new Synaptics driver on my Inspiron 15-5547.