How to manually move all your preferences files to another CC app installation?

During the install of CC 2018 an Advanced Options pull-down menu appears. Within that menu is an option to remove old versions plus an option to keep previous settings and preferences. By default both of these are checked. This is why old versions have been automatically deleted by those who were not aware that they had a choice in the matter. The second option, however, to retain old preferences has, for many people, been the cause of slow and dismal performance for the new version of the program. So it has turned out to be better not to pick up your old preferences. To read more about this and how to deal with the poor performance from using old preferences please see this post from the Illustrator FAQ: CC 2018 Illustrator—Don't Import previous settings and preferences .