Hi all, happy new year ;p I recently upped my ram on my MB to 4gig for my Windows 7 ultimate to which my pc now states i only have 2.9gig usable ? guess thats the 64bit OS eating at it ? anyway my question is :- What determines the maximum ram a MB can handle ? Reason i ask is because my dad has an old Imedia which states its maximum is 2 gig but he has 3gig installed and windows recognises it and it runs fine with no issues. My ixtreme has two slots and i want to know what would happen if i put 2 x 4gig trips in ? PackBell state 3 gig max but is that because the pc originally came with 32bit vista or is it a MB thing ? Hope some one can clarify this for me. Regards, Lee.