Need some input on upgrading

[ixtreme-m3720]

Hi

I've been facing some severe FPS lags in League of Legends and trying to improve for months now. Been playing the game on very high settings flawlessly for 2 years, it's just not cutting it anymore, and not sure why.

Their support has not been helpful, and I've tried pretty much everything imaginable when it comes to drivers, other programs, reinstalls etc. Also worth mentioning there's hardly any difference between medium and very high settings!

I'm tired of the hassle and will upgrade, but not sure how much I actually need?

Computer is a PB ixtreme 3720
CPU Q8300 @ 2.50ghz
4gb ram
GeForce GTX 460
Corsair CX 430W ATX

According to their support, requirements, my historical experience, the rig should be fine. But it's not! So I'm a bit worried about buying a completely new machine for £500-600 and not see any improvements.

Any recommendations on whether I should swap any parts, get something completely new, and if so - what?

(I'm not intending to play any modern high end game, I mostly play LoL.)

Thanks

 

[ixtreme-m3720]

No SSD drive, no..

Thanks for the advice so far, was a good read, could be worth investing in a new PC.. I'll make a new thread as advised