When Windows is reporting it, it is based on combined resources - available memory by any means. Technically, resources does not just refer to memory but generally speaking that is what it comes down to. Depending on what you have for RAM, you can make adjustments via 'System Properties' in ControlPanel. Even if you choose the "Let Windows Adjust.." (approx) button it can usually help your cause if machine is bogging down. It may not optimize memory perfectly but it should be improvemnet. I''ve challenged it over the years and it does pretty well.