Additionally, Foxconn has no support page about their motherboard, and I cannot find any way to contact their tech support; Gateway refuses to support me about this question, and referred me to Foxconn.
Was it faster when you first got it? Even a quad core that slow shouldn't have any problem running windows and daily programs.
What are your main uses for your pc? What operating system are you using?
Some retail pre-builts come loaded with bloatware which can really slow you down. (I remember compusa trying to charge my dad $100 to 'clean' his laptop before he got it, it was as easy as add/remove programs; uninstall x10)
Download cpu-z and look under the mainboard tab. If your mobo model is the RS780 (I'm guessing it is) then it looks like you can use up to a 95w phenom ii 945, which is an awesome cpu. Just make sure its the 95w version. Just don't expect your bios to fully recognize it or have any oc capabilities, but it seems to work.