Okay, so I'm upgrading my 512mb memory into a gig. Originally, I had 2 X 256mb sticks. So, I went and got 2 X 512mb sticks to put in there instead. Now, they are sitting in there (took the 2 x 256mbs out) because it wont work. I've tried every combination I could think of...with 256s in, with them out, different slots, etc. It wont work! It keeps restarting before it even loads the desktop! The only thing I can think of is that its not shoved in far enough (but i put them in quite well). The other thing is that they aren't identical! I mean, they came in the same type of packages, but when I took them out, they are different...One says "win" the other "pc" and they are structured different. They don't level with eachother either. However, the packages are the same...pc2700 ddr 333mhz...if anyone could help me out I would be sooooo grateful. Thanks muches!