Yeah. Your system is a little dated. RAM isn't listed, but that's ok. You have a 1st Gen i3, integrated graphics, and a 300w PSU. You could upgrade the i3 to an i7 860 or 870. There are a few GPUs that can run off a 300w PSU but they are very low level GPUs. If you wanted any moderate GPU, you would need to get a better PSU as well.
My honest opinion is to scrap this computer and start fresh. There is nothing wrong with it for everyday use. However, for gaming, it's pretty low end. A $500-600 PC with today's hardware will be miles ahead of your current computer.