There are 4GB of actual, physical RAM free when MA3 is running. I don't think memory is the issue.
It may well be true that memory is not the, "
problem"
, - as Vista, apparently, is said to be very good at managing virtual memory.
(BTW, that article is referring to
virtual memory, not only actual, physical RAM).
But surely it would do no harm to reduce some of the bells-and-whistles? - You have already stated that disabling McAfee makes some improvement!
If you do not wish to try
anything, that is your prerogative, - we can only offer suggestions when asked...