I am using Windows 7 64bit. I have 3 2gb RAM sticks. I booted up my computer and i went to control panel and looked at the System info and it was showing 4 GB of installed memory. I checked CPUZ and it was showing 6 GB on here. So i am not sure if windows is actaully using the 6 GB because one place it says 4 GB and another place it says 6 GB. Is there some other software or a sure way to check to see if windows is using the 6 GB?