Can I install 3GB of memory in my dual-core CPU?

go for it... it will work but look at the ram your currently using. the link u posted is to DDR2 533 my guess is you have the more popular (and faster) DDR2 800 installed. this will cause the 2 GB of existing RAM to down clock to 533MHz as well. which is not really an effective means of gaining RAM. Yes you will have more but it will all be slowed down. Just make sure the RAM you purchase matches your existing ram in size and speed (make is not a big concern).