I've got a Nvidea Geforce 4 (MX440) graphics card installed, but want to up-grade to something better. There are lots availble on Ebay and elseware but what Key slot configuration do I want? Mine has 2 slots and fits my PC connectors, but there are some available which have only 1 Key slot and would fit a AGP connector. which I have on my MB. Can I replace my 2 keyslot card for a 1 keyslot card? Please