Ok, I am gonna try and give as much info on this as possible, I have a Hewlett-Packard Pavilion XE783. I have 64 mb of RAM, and I am attempting to upgrade to 256 mb of RAM. I went to this site www.all4memory.com Someone from this site recomended it. So i got the correct type of RAM for my computer, I downloaded installation guides, and decided to install myself. I remove the cover look inside and find my current RAM stick in it's slot. Next to it is another slot for RAM, I install the new RAM in the second slot, and left the old RAM in its original slot. I boot back up, and go to see if I had succesfully completed this task, I did not, still reading 64 mb of RAM. My computer is old 1999 I think is when we got it, so I went to get a BIOS update, downloaded instructions and performed that task, then I uninstalled the new RAM, and re-installed it, I still read at 64 mb of RAM, now I don't know what to do, should I remove original RAM stick? Will something like that harm my computer? I am confused and all4memory.com's tech support is very slow to email me, so I came here, hope someone can help.