32 bits. That's your problem. That limits Vue to use only 2GB of the 4GB you have. Every new software release (not just from e-on's) demands from the hardware. That happens with Microsoft Office, with 3DS Max, you name it. Vue is no exception.

64 bits systems (and a good amount of RAM) are more and more required for doing any serious work in Vue (or many other 3D apps). You should seriously think about upgrading your hardware.