Did they include the program on discs? If so, the additional content is included on the supplemental disc in the box.
Otherwise, it's likely to be tough if not impossible to locate support files for this nearly 5 year old program. I'm not sure why someone is selling computers with old versions of software pre-installed on it.
As has been the case since Premiere Elements 10 was released, there is an online link to Premiere Elements 10 Content.
This is the link
Is it not working for you or have you just not found it yet?
Please also refer to
Please let us know if that worked for you.