Even on the highest settings GUild wars 2 only calls for : GeForce GTS 450 2GB DDR3
Radeon HD 5670 1024MB
either of those or higher. Your M7950 is a bit dated, and is going to have an issue keeping up with those. Replacing the motherboard isn't going to remove those DUAL Nvidia GeForce Go 7950GTX video cards, they are 512MB a piece, which brings total video up to 1GB, but it's still a very dated card. You have multiple things in this AW that are just dated, and need replacing. The HDD is small, the GPU's are pretty much useless by todays standards ( they workd.. but not well ), it DOES have a nice screen. But like i said, even if you could replace the motherboard, there are other factors that will go into everything else. The ram in this AW is DDR2, so you would need new ram, just.. to many things overall. sorry i didn't have a better answer for you 🙁