If you want high FS2004 performance for the lowest cost and don't care about what FSX needs:1. Keep your 1G RAM and X800 - they are plenty enough for FS20042. Buy a mid-range Core 2 Duo CPU and motherboard that will take the type of RAM and graphics card you currently have. I assume you have DDR RAM and an AGP card, so something like the ASRock 775Dual-VSTA would do the trick.Total upgrade cost - $60 for the motherboard and $220 for say an E6400, gives $280 total. With this upgrade and the addons you mention, I'd say you'll never see below 25 FPS again!Now, if you care about what will also make FSX scoot along, you're going to need a much bigger checkbook :-lolGary

Thanks for the information

Also how do I know that, that motherboard will fit into a Dell 4500 inspiron Computer?

As long its an ATX form factor, then the sizes are standardised. But you will probably need more power, unless you already have a 450-550 watt power supply.Allcott

Ok cool thanks for the info

Actually, if Aerobus goes with my recommended upgrade, the system power needs should be about the same, and maybe less. ie. same peripherals, RAM and video card, new motherboard (maybe a little more power because of higher bus speed support) but with a very power efficient CPU (probably less power that what his current CPU uses).Gary