Note that a typical mistake (so to speak) is not to uncheck all 3 checkboxes. Each checkbox has it's own purpose related to the sponsor, and i've found out that the first one is sometimes left untouched by people installing the software
mostly because it's not aligned with the other ones so it's "hard to see" if you're rushing through the setup.
Also note that the first checkbox is the one that asks if you want to install the toolbar, if you uncheck that one all the checkboxes are unchecked aswell. The thing is that you may have unchecked the second and third checkboxes and left the first one checked (it even happened to me once and i've installed it a hundred times).
Long story short: The toolbar wont be installed if you don't agree to it, i'd suggest you to download the installer again and see for yourself what i've explained above.