I bought a computer from staples, (link: http://www.staples.ca/en/HP-ENVY-Desktop-750-229-3-2GHz-Intel-Core-i5-6400-8GB-RAM-1TB-HDD/product_2071430_2-CA_1_20001) but when i got it, I realized the graphics card is terrible, a gtx 745, and i was wondering if i could replace it with a gtx 970 or if i had to buy any other parts aswell. I don't even know if i can replace the graphics card or if the gtx 970 is compatible with my motherboard and other parts. If you need any external info or links just comment telling me what you need.