http://www.lavalys.com/products/download.php?pid=1&lang=en Thanks for your information. It dawned on me that the best and most practical way to find the answer to my question was to open up my computer and see what the 250 mg that was already in there was. I was going to need to open it anyway when I got ready to put the new RAM in. So now I have bought myself a twin. I will download and run the program you recommended as well. It looks interesting. Bettye