Try as you may, your computer's OS will NEVER see more than about 3 gig's of ram in 32 bit mode.
In 32 bit mode, there just are NOT enough bits to address any more ram than that.
Fiddle and fahrt around with it all you want and you're NOT going to change that basic fact.
To address and use over 3 gig's of ram, you MUST install and run a 64 bit version of your OS.
A 64 bit capable CPU will help too.