For now, the previous commenter is correct. You need to help him order RAM online and maybe you can even show him how it installs using youtube videos and tools you may have with you during your visit. In so much as most desktops have as many as four memory slots, it would be wise to open the pc anyway to determine the best fit. You really only need to get him to 2gb, but of course 4 would be nicer if he can afford it.