Windows will use all the RAM it needs, unless you instruct it otherwise. There is a setting in msconfig to limit the amount of RAM, so just make sure that is not set.
System Manufacturer/Model Number Gateway/NV7923u & NV79C52u Laptops OS windows 7 professional & ultimate 64bit laptops CPU 2.27 boost to 2.53 & 2.53 boost to 2.80 Motherboard Mobile Intel® HM55 Express Chipset ??? Memory 4GB Graphics Card Intel® Graphics Media Accelerator HD Sound Card realtek High-definition audio support Monitor(s) Displays 17.3 " HD 1600 x 900
Hard Drives hatachi Travelstar 5400 500GB & west digital 500GB Internet Speed 35MB fios