Just built PC running games extremely slow

ModiFkrz

Prominent
Jul 15, 2017
7
0
510
I just built my first PC and everything runs fine except games. My old laptop runs games better than my new system. Everything is new except the hard drive which I got from my old laptop. I've reseated the RAM, GPU, and CPU, but nothing is working. I still have warranties on everything except the GPU which I bought brand new last year. Any help is much appreciated.
System specs:
Ryzen 3 1200
PowerColor R7 360
MSI B350M Gaming PRO
EVGA 500w White 80+ certified
5400 RPM 2.5 HDD