I have 2x1gb sticks of A-DATA ram currently but I think more would be useful. The only problem is I can't find the exact same ram again. I know your not supposed to mix ram but if I got another 2x1gb sticks of A-DATA ram with the same voltage and timings would it work. I don't need any more ram but I think I could get my machine running a bit more efficiently if I had some more. I'm currently running vista 32 bit (and know it won't use it all), but I'm going to switch to 7 64bit next year because I'll get the student discount.