Hey, I have a Tagar AMD Athlon XP 1800+, 1.53 GHz, 224 MB of RAM. My questions are, first, I want to upgrade my memory(RAM) and Im looking at purchasing a 512MB stick from tigerdirect.ca but Im not sure if this kind of memory will be compatible with my system. The one im looking at is 512MB DDR but how do i tell if I have DDR or SD Ram without opening the CPU? Also, I want a new video card. And im looking at this http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=1020528&sku=V261-3032 how will i tell if i have a PCI slot or the other? (or just how will I see if this video card is compatible with my computer) thanks for your response in advance and im sorry for the length of this document its just im a newbie at upgrading and need a few questions straightened out. Thanks alot.