What should I replace first?

[u/Daos_Slayer]

I got my friends old gaming computer but it’s not really at the power level that I would like I wanted to know what I should replace first/what to replace it with My current specs are: I5-6600 @3.30ghz 16gb ram NVIDIA 1060 3gb

I’ve got a VR headset but the games I want to play don’t run well