I am new to PC gaming and i want to play games on my pc like Grid, Dirt and other titles like Bioshock. But, i have an old pc that has intel pentium dual core inside and cpu of Intel Pentium E2160 / 1.8 GHz with 0.99GB of RAM. Can i even upgrade or should i just build one from start? I dont know much about this, any help would be greatly appreciated.