If the downloads work for you and you don't mind the bandwidth usage, simply use that. It's merely a matter of where the installer stored the install source path and since you converted the trial, it stil lpoints to that original source. No need for any of the DVDs from a technical POV.
As mylenium said use you already installed setup to install PRE 10 , just use your serial to serialze it....However for your info of the DVD
DVD description section
Thank you both for responding.