i have a emachine desktop and i need new memory and i have an older dell desktop i was wondering if i could take the ram out of my dell and add it to my emachine? this is what emachine.com said about my pc ... 512MB DDR (1 × 512MB) 400MHz (PC3200) Expandable to 2GB and i removed the ram from my dell and it says 16Mx64SDRAM on the ram card... is this ram compatible with my newer pc?? im wanting to add ram because i am trying out second life and its lagging and freezing and im under the recommended ram and figure thats why its freezing on me.. is ddr and sd two different types of ram?? if so i wont be able to add the card will i???