missing screws

I just got a secondhand IGAME 1070 when i received it everything looks fine until i took the gpu from the static bag a screw fell off and the whole fan part is dangling, the seller only stated that theres a screw missing i thought it was just one screw apparently the fan's plastic screw housing...

I know there had been a lot of thread similar to this but I still have a lot of noob questions, please bear with me. I have a Seagate 1TB HDD, only have it for about 5 months. Recently it's making a lot of grinding noise, and everything freezes or my pc restarts completely. I ran HDTunes and...