Odd. 32 bit Windows should show up to 3.5GB of memory. Sometimes however with some motherboards it is limited to 2-3GB. Did you just "upgrade" to media centre? Or did you wipe your system and start again? Because something may have gone wrong there. I would have thought that some system information should be shown too, so that may indicate something wrong (as mentioned in posts already). Also, my 32 bit xp installation finds all 8GB of my memory in CPUZ, but it doesn't mean that it can use it. It's just the way that CPUZ finds the memory.