I am contemplating fitting extra memory to my pc. I have checked on Crucial to see what I need but my pc manufacturer is not in their list. It did run a scan on my pc and came up with the following info. The maximum my mobo will carry is 1536mb. In slot 1 I have 256mb non parity pc3200 memory, in slot 2 I have the same and slot 3 is empty. My OS is xp home. My question is, Should I fit an extra 512mb in slot 3 or should I fit a 512mb in slot 1 and 2 and if I fit a 512 in slot 3 is there any particular order they should be fitted or is it ok to leave the 2x 256s where they are. Hope this makes sense.