I have a few last desktops (HP d4999t and d5000) with similar CPU. The thing is that the CPU heatsink is prone to lift off and I just leave the kit with some paste handy when I suspect it's come off ago.
I bought my PC off my buddy last fall and up until now it's played everything fine on medium to high settings. Lately, whenever I play Guild Wars 2 I get like, 9-15 FPS. It's not a ping issue and the game used to run perfectly, so I don't think my computer can't handle it. I also have quite a bit of space on my computer, so it has no reason to be slow. My driver is also up to date.
My specs are:
Windows 7 Pro. 64-bit
Intel Core 2 Quad Q8200 @ 2.33GHz
AMD Radeon HD 6670
Any input on what might be up and/or advice on how to fix it would be suuuper appreciated!