Kindve an old processor, but it should be alright. If you want to replace the processor, you will have to buy a new motherboard too. I reccomend the AMD 955 Black edition quad core. If you want to upgrade your GPU, I reccomend the gtx 460
Before we start suggesting what you need, what does your computer do or not do thats Fracking you off? If you love playing video games then your GPU could be upgraded. If your always getting annoyed because that filter you applied in Photoshop 2 min ago is STILL not done then a new CPU will help. Don't forget about your ram or PSU as well. 2GBs of ram isn't much, and a junk PSU could blow when you install that shiny new GTS460.