If it is a desktop, you can replace the power supply and the video graphics card, and perhaps that will do the job. That isn't possible with laptops or with a majority of "All in One" hardware.
This is a more current version of a minimum video card (medium screen resolution and LOW graphics settings, with "moderate" 40-45 FPS screen animation rates):
To which you would then add this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139051
I have used Newegg as an example only, due to the wide range of the offerings. They only sell in Canada, China, and the United States.
