here's a couple starters, when you opened up your mobo, did you see what kind of mobo it is? if you can check (the name should be in the center of the mobo) i can check if it is dual channel ram capable, while your at it, see if you can see the brand of the ram, if not, its alright, it just seems weird to me because ddr266 is pc 2100 not 2300
http://www.newegg.com/Product/Produc...82E16820144001
http://www.newegg.com/Product/Produc...82E16820145024