I have one 512 (DDR PC2100) and one 1GB (DDR PC2700) stick in my Asus K8U-X motherboard. So, I'm below the motherboard max (2048MB) and below Windows (non-Pro) max (3-3.5GB). It's not Dual Channel (confirmed by crucial.com). My Video card is 256MB (I'm not entirely clear on how they interact, but I know that's important).
So, when I check on System Properties, it's only giving me 768MB. What am I missing here? Any help would be great - I'm trying to upgrade my system bit by bit, and this is a bit frustrating. Thanks!