Upgrading RAM

I'm trying to upgrade the RAM on my Dell and am kind of confused. I have 2 slots in my computer, one of them is empty, and the other has a 512 MB DDR-SDRAM. My computer can handle 2048MB (Of RAM). So does that mean I can just put a 1GB DDR-SDRAM into the empty slot and combine the two?

if you are gonna keep the RAM you already have in there you might want to find out what RAM it is.

Then when buying some more try to match it !

But to answer your question, yes, you can buy 1GB and add it to what you have.

It is 512 MB DDR-SDRAM, so what I was asking was if I buy another DDR-SDRAM to add on to the empty slot, I can use both.