Questions about buying Computer Ram?

It seems like your best bet is number 1. Your memory is DDR not DDR2. The pins have a different amount on the bottom. The gold stripes on the bottom. DDR is 180 and DDR2 is like 240 pins. And the little cut on the bottom is more towards the middle. So you can't force it in either way. I think it might be time to upgrade. How many years have you had that computer?