I'm in the process of upgrading my computer and I have some parts but I'm getting a little irritated that my computer is running so poorly. Right now I run around with 15-20 FPS, and that's without doing anything. Was wondering if any of the parts that I have now for my new build are compatible with my old computer so I can swap out parts for better performance until I finish the new build.
My first thought is you need to dust off the heat sync and replace the old thermal compound for your CPU seeing as that system is 5+ years old. The same might need to be done with the GPU but for now, you can start with dusting it out.
Assuming you're talking about WoW you should be able to use graphics preset 3 or 4 with acceptable framerate at 1080p. You might be able to push preset 5 if the resolution is less than 1080p. You really need a better video card if you want to use preset 7.
I'd recommend getting no less than a gtx 1060. I know this card is overkill for wow currently but you can expect it to meet or exceed future requirements as new expansions come out instead of just having enough to get by. Also it's great for playing modern titles.
Mana has the right idea, most of the stuff you have listed as new really wont help your performance much or even at all.
The parts he had listed, the difficulty of changing these parts are such easiest+gain first
GPU, your current supply can handle most GPUS.
Ram: same set super simple just click the new sticks in.
SSD and cooler: cooler "can" be a pain to change, dont forget thermal paste. SSD is easy to install but may need to look up guides on how to mirror as your biggest gains from it will be from boot times and load times in wow (at loading screens or long distance renders)