If you are running it on a 32 bit OS, then your applications are limited to using 2GB and the rest of it used by the OS in itself. However, using a system wide 3GB switch, this can be changed to allow applications to use up to 3GB and even this may not guarantee that you see the available memory increase when the LARGEADDRESSAWARE flag is used because, this increased memory could be distributed in different ways depending on the applications you have running.
On the other hand, if you are running it on a 64 bit OS, it could be that the available memory increase is limited by the hardware itself (available RAM space).
