I'm at work right now i will have to get back to you on that. I dont know the specs bye heart. I bought this from my friend. I just know its a AMD duel core, NVIDEA GeForce 8400gt card, power supply and motherboard...again I will post later.
I have no idea about Skyrim, but Battlefield 3 isn't going to run on an 8400GT, that video card is incredibly weak and BF3 is one of the most graphically demanding games out. BF3 should run on a 6570 with low settings and a low resolution, but the experience won't be the greatest.
Depending on what AMD Dual Core you have, you may or may not be able to run the game. Minimum is an Athlon X2 5800 or so, and online multiplayer gets more cpu demanding as player counts increase.