DirectX 10 with windows 7 is not compatible at all. It arises the problem whlie playing a game. So i think you have to WindowsXP with directX because it is lighter than windows 7. It will not create big trouble while you are playing a game.

Yes, you can easily update your graphics card. It will increase performance in graphics and it widely used when you are playing a game. So you have to update easily with the given instruction on the disk.

I have Nokia 6233. But i want to change and i am preferring iPhone. Because iPhone has great features and functionalities. It allows portable hard drive usage, 5 mega pixel camera, strong battery power. It also contains some additional features. So i will go with iPhone.