|Total Physical Memory 4,096.00 MB|
shows the system is seeing the 4gig.
this is what is wrong
Available Physical Memory 1.46 GB
This does seem a bit unusual in that the system device drivers are taking 2 to 1.5gig. Usually we see 3.25 or 3.5gig available to the system.
Review your boot.ini and make sure there is no "maxmem" statement which can limit the amount of memory the system sees.
Put in a lower end video card and see if there is a difference.
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