nothing; don't waste money on an upgrade.

instead; save up about $700USD and buy a new one.

it's much better value-for-money, and you will get a nice new computer too! your current computer is too old for it to be worth spending time and (more importantly) money on.

even if u upgraded ur ram and video card, ur cpu will still hold you back, seriously it's a POS, i core 2 duo E6300 clocked at 1.86ghz would perform bettr than that, also ur cpu says dual core but really it isnt true dual core, it's really more of a single core modded to be dual core. so take bullet magnums advice and just buy a fresh computer, it's probably the easiest option.

you may have one of the earliest dual cores on your hands, but you may be being lied to you (with a clever technology that Intel uses).

either way; spending money on that computer is money wasted.

i don't know how much money you have currently, or when you'll depart with it so take the following with a grain of salt. this is what i would recommend to a gamer-on-a-budget; it's got plently of grunt at a cheap price and is moderately upgradable in the future.

CPU: AMD Phenom X3 720,

GPU: any HD4830 (don't get me wrong, i love my nVidia card to death, but ATI's current crop of cards are superior to all but the really high-end nVidia cards),

RAM: 4GB of DDR2-800 (as cheap as you can get it)

Mobo: anything with a 790GX chipset.

you can recycle your old case and hardrives, you may need a new power supply, but ask your local computer geek about that as it's really something that should be done in person.

just remember; this could become out of date at any moment (and if a random person is reading this in a months time, it could be out of date right now). be sure to do your own research and fact-checking, it won't be my fault if you don't.