If you read the recent reviews of this processor on NewEgg you'll see that the general opinion is that it is outdated. I also looked at specs for an Inspiron 570, that's fairly old hardware too. It looks like it will handle a maximum of 8GB of RAM, it's got onboard video, I'm not sure if it even has a slot for a PCIe video card it looks like it does have a PCIe x16 slot. Also if you haven't already upgraded the power supply, you'll probably need to if you want to install a video card that requires auxiliary power connections. If you have the money, I would recommend building a new computer.

It would help if you answer jbmcmillan's question about what games you intend to play. It would also help if you told us what your budget is for a "gaming" computer.