My resolution is 1280x1024
Would a GeForce 250 work? I'm not a fan of computer upgrades etc.. what is psu and how would i check?
It's the power supply unit. The block you plug the power in. Just open the side of your PC and check the label, it should say the wattage. Also take note of the brand as well.
For the GeForce 250, it should work for MW3, however, it will be struggling with BF3. I'd suggest GTX 460 at that resolution.