What do you mean my pc model dg31pr

DG31PR----That is your motherboard! It's an old model and I believe has onboard graphics! Mostly all games today require a separate GPU (Graphics Processing Unit) aka, Graphics Card. In order to run such games, you need to purchase a separate graphics card as onboard graphics are just not good enough to run games.

What CPU are you running? Post the remaining details of your computer (CPU, RM, PSU, Hard Disk, etc) and then maybe we can offer some help.

As posted, DG31PR is your Intel motherboard. It's a classic version and it does have inbuilt graphics in it. I used to have this same motherboard. You have a PCI-e X 16 slot, so you can buy a good graphics card, considering you have a good processor and a good CPU and let's not forget, your budget. From reading your clock speed of that Intel processor, my guess is that it's a E7500, the same CPU which I have.

So, if you want to play games you need to have better than onboard graphics, like the one you have. You should have a good graphics card too. We can recommend you a good one, provided you tell us your budget and your PSU.