With the other Canon software installed you may (but I'm not certain) be able to install the upgrade version downloaded from Canon's website. But if you do you should also download and install the updates for all the other Canon software as well so as to be sure they'll talk nicely to each other. Certainly worth doing for DPP as extra functionality has been added.
I did try the upgrade from Canon website but the software refused to install, it just came back with a warning about wrong OS so I gave up.
Probably i'll just buy a CF card reader and use that. It was only the EOS UTILITY that would have been usefull but I can manage without it.