Re: Will this make a good gaming PC?
Trying to improve a prebuilt system is never fun. OEMs use crap cases, crap ram, crap mobos, crap psus, the cheapest cpus they can get. In short almsot everything is lowest bidder.
The motherboard is the foundation of a pc. If the mobo is crummy then you can expect a lot of headaches down the road. No overclocking, not enough expansion slots, not enough sata ports, the list goes on.
My advice to you. How much do you want to upgrade it? If you want a performance cpu, killer video card and a nice 3d mark score be ready to throw out a lot of parts and spend some cash.
If you just want to get a reasonable video card then be sure to grab a psu that will take it. Puddle has a good pic there, Corsair's psus are top notch all the way.
Figure out what you want out of your pc and we can help you a great deal.
I hope you haven't bought your parts yet. It is never a good idea to buy performance parts and hope they work with a prebuilt system.