We could not complete your purchase. OS X Mountain Lion is not compatible with this computer

Hi guys!

Please, help me!

I don't know what's going on,

I have an early 2008 white macbook and I went to mac store with it to ask some questions and they said my mac can

run a Yosemite version, I would only need extra memory Ram.

BUT I don't mind to have the Mountain Lion for now (at the moment is Lion version).

The problem is I bought online the 10.8 version (Mountain lion) and when I hit on download, appears

this message: "We could not complete your purchase. OS X Mountain Lion is not compatible with this computer."

And below is my mac configurations:

Hardware Overview

Hardware Overv