Adding ram to your system requires that you know:
- What the maximum capacity of memory (and type of memory) your motherboard supports
- How many memory slots there are
- How much memory you currently have
- How many slots are currently in use
So, you need to know about your motherboard/system.
If you cannot find this information on their website, provide the make and model of your system/motherboard.
Now, for a processor this old, you should not get your hopes up.
Perhaps you can explain what you want to accomplish? Faster gaming, better performance, upgrade operating system, etc.