Reddit mentions of GeForce GTX 650-1 GB GDDR5 - PCI Express 3.0 (01G-P4-2650-KR)

im not the best these types of things but this is from my knowledge.

the problem is the graphics card, as you said you have a 'NVIDIA 620 Graphics Card' which is a GT card and is old and quite bad card... i would recommend buy a new card of the GTX variety, it depends on how much you are willing to spend on a new GPU but as you said ' I purchased Farcry 3, and I can barely run it on the lowest resolution and low graphics ' if you want to play FARCRY 3, i would recommend a GTX 650 which will allow you to run the game at about Min-16 Max-29 Average-23 ( taken from a GTX 650 test video on FC3 ) if you want maybe a better FPS / GPU then i would go for any higher graphics card like a GTX 660 (i previously had the GTX 660 TI SC) , GTX 670, GTX 680 (currently have GTX 680 SC) etc

i hope this helped and i understand that it was a easy 'get a better GPU' answer but since you said you dont know much, i wanted you to know why you need a new graphics card