[url]http://www.systemrequirementslab.com/CYRI/Requirements/crusader-kings-ii/11260?p=r[/url]

Here's the minimum requirements. There should also be an option for you to have the site evaluate your computer, and tell you if you meet the requirements or not.

Edit: The part that says "Click here to see your results" under the "Crusader Kings 2 Minimum Requirements" header.