To save you a ton of time looking for the PDF preset folder for InDesign CC 2014…
Here is is:

C:\Program Files\Adobe\Adobe InDesign CC 2014\Resources\Adobe PDF\settings\mul

If you place presets there, your users will not be able to modify the settings.

If you do want your users to modify the presets save them here:

%appdata%\Adobe\Adobe PDF\Settings