I agree with The Paladin, you should get a ssd for your OS. The i7 still has plenty of legs. I see no problem with the build other than the power supply. Look for a 650w gold modular.
Is this what you have or are looking to buy? Parts or pre-built? For what games?
this is what i have....i really dont have issuse with it just want to know what can be upgraded i play ROTR, BF1 and so fort and play pretty good
I wold not cal BF1 a "moderate game" it's one of the most demanding games for hardware out there.
Get a good power supply, upgrade the video card if you want, SSD is good also but won't help with game speed really. SSD will make the system faster overall with loading programs and response time. If there is nothing wrong with games on the system, a better power supply would be the first thing.