I'm normally good about finding my own answers on the internet, but I'm a bit stumped with this one and afraid to take a chance. I was previously using 1 stick of RAM. Here are the specs: 1 GB DDR2 667MHz (4-4-4-12) 1.8v Product Page I just bought a 2-pack of 1GB sticks with, as far as I can tell, the same specs. Product page I removed the old one and installed the 2 new ones per the Mobo manual (putting them in same-colored slots for "dual channel.") Computer started up and is running fine. Here's my question... would it be okay to install the old stick along with the 2 new ones for a total of 3GB? If there's a risk, I don't want to do it... I'll just buy another identical twin pack and go for 4 GB (well... 3.5 GB useable because I'm still using XP ... FTW!) I just hate to see that 1GB stick sitting there on my desk not doing anything. Any help here would be appreciated.