I wouldn't do that. Core 2 Duo is pretty slow and the platform is ancient. Better to just get something modern, pay a little bit more now, but get a more reliable, less problematic, and frankly better system.
How about something like this? Its a Core 2 Quad. http://www.ebay.com/itm/Dell-Precis...hash=item1c4b84648e:m:mCEGWKWC7HVtVv2YXyqcllQ