What do you think i should upgrade on?

Hello Forums, I've been having some hard decisions on what i really want to upgrade mainly on my gaming computer. I've been having problems with my computer it seems to be slower than before like, windows takes longer to boot up than usual , everything takes more than a few seconds to load like, programs, games and fps on games seem to get so garbage.

Here is my current build for my computer:

MSI 970A-G45 AMD 970 A socket ( Might go for a Asus sabertooth 990FX)

Galaxy Geforce Gt520 ( Planning on getting a 7970 not as sure yet)

Kingston XMP 8gb 1600 ghz DDR3

Cooler Master extreme 500w

Hitatchi 1TB ( Might get a new hdd with a ssd not sure)

Coolermaster CM 690 II Nvidia

Amd FX-4100 x4 @3.6ghz

What do you guys think i should upgrade mainly?

Thanks.

 

If things are lagging, or loading slowly, have you tried reinstalling the OS? That may help a bit. Your power supply is a little on the low side, Maybe upgrade to a 750W or so. A Graphics card is always a good way to go when upgrading, Your ram seems fine, and shouldnt need an upgrade. What speed is your hdd? If its 5200 RPMs, then deffinately upgrade it, too. If its 7200 it should be fine. 

i would get the 7970 , fx 8350, and a better power supply something like corsair cx 600

redo: depends on how much you wanna spend

I've reinstalled the os system twice and still it acts the same as before. The speed for my HDD is 7200.