Win XP (32bit) can only support up to 3GB of RAM. So unless you are using win XP 64 bit, then that is probably the problem you are running into
You are most likely correct and I have given up on trying to install the 2GB to 4GB upgrade. Some of my friends say they have doe it but none of them had volunteered to come over and show me. Thanks for you help, sorry for the delay in getting back to you.