Sorry - works for everyone else! Creating a new user is a known work around for some software installs not just Canon's DPP. Try running ONYX (Google it) first then try an install with a new user again.
You might be trying to be too complicated. sign in as normal, Sys Prefs > Users & Groups > Click the Plus sign > create a new user. Back to your normal user > Log out > Log in as the new user > install software. Delete the user profile when it's inst...
When you install for the 'new' user you get the option to install for all users, once it's installed, login as your normal user and DPP will be available to you, I then deleted the user I made to install it and DPP is now available in my normal user ...
