I'm pretty good with computers but I'm not familiar with upgrading my PC's RAM. I have a HP Desktop with a 3.0 GHz Pentium 4 processor and 512 MB of RAM. I'm interested in upgrading to at least a gig of RAM. What are the steps I would go through to do this? I'm not necessarily asking how to get inside my computer and upgrade it but more like how do I know if a certain stick of RAM is compatible with my computer. Also, do all computers come with two slots of RAM? If so, does that mean I could buy a 512 MB stick and my computer would end up with 1 gig of RAM? That doesn't seem likely but again, I'm not familiar with RAM upgrading.