How to make my computer better for gaming?

My computer basically sucks, but I can run simple games. Nothing like DayZ or something like that. However, these "simpler games" are not running as well as I would like and crash a lot. I want to add some things to my computer to help it run. I would be willing to spend 200$.

Here are some specs:
Lenovo
Intel(R) Pentium(R) CPU
G6950 @ 2.80GHz
1.17 GHz, 1.92 GB of RAM

I know it is awful, that is why I'm looking to upgrade it without having to buy a new computer.

This is best computer for gaming:
emachines tower with:
Pentium D 930 3.0Ghz
1 GB DDR2
250GB HD
ECS motherboard that supports a C2D.

Con 200 pesos note alcansa nada, necesitas otro procesador o una targeta grafica pero en este caso te urge mas el procesador. Mandame el model de tu placa madre

Add more ram and clean registry

Get a graphics card, i5 proccessor and atleast 4gb of ram.

Dump it and spend some money - you'll be much happier in the long run. Your PC is seriously obsolete - don't you deserve a new system? YES, you do!