It happened to me that i lost my original Canon CD supplied with my digital camera. I got new PC and needed to have DPP installed there. I downloaded the DPP update from Canon site and installed it. To install  Canon DPP update without having previous version installed, open Registry Editor and create section HKEY_LOCAL_MACHINE\SOFTWARE\Canon\Dpp.

Then run Canon DPP update installer and it will install full DPP version successfully.