GPU not working (HELP!!!)

[Alotelli]

So i upgraded my gpu to a vega 64 recently. When i turn on the pc, the fans were spinning and the led lit up. i plugged it to my monitor using displayport, and it booted fine. But when i try opening fortnite it says "failed to find a graphics adapter with the minimum required dx11 feature level". When i open overwatch, the game boots but with crappy graphics. What can i do to fix this. 

 

pc specs: 

i5 8400

corsair vengeance 1x8gb 2666 mhz

mobo: asus prime h370m plus

gpu (old): msi 1050 ti gaming x

psu: can't remember exact product but it was rated 80+, non modular, 500 watts.

[G00fySmiley]

first question, did you add the drivers for the graphics card? also as you had a Nvidia graphics card I would uninstall those drivers before installing the new drivers