I've down a little research now, so I think I have a handle on what I need, but I want to make sure. I've got a Dimension 8300 with a 800MHz FSB, which means I need DDR400. Right now, I've got two 256M modules, and I have a total of four ports. New memory must be installed in pairs. So, if I go into the store, what do I look for? I believe it's PC3200, so is that what I look for? Any PC3200? Is PC3200 synonymous with DDR400? There's something in my manual about memory being limited to the slowest memory, so I want to make sure I don't hobble my system with the wrong memory. I'm either going to get a pair of 256s or 512s, if that's important. Best Buy's having a special right now, but I threw out the flyer. I hope what I need is covered.