You will easily conclude I am an amateur! I have an AMD Athlon 64 with 2 x 512MB RAM in 2 (green) of the 4 available slots. I have purchased 2 compatable (PC 3200) 512MB to increase the memory to 2GB. When I instal one of the sticks all wroks well instead ststem file does not recognise the new stick. When I instal the 4th stick computer decided to shut down info sent to the screen. Crucial.com tells me that I can have up to 4GB onboard so how do I get the 2 up and running. Do I need to enable to other 2 slots and if so HOW????? HELP!! Thanks, ToDe