Windows is lying to me?!!

It's Turbocache (Hypermemory for ATi video cards).

Don't worry about it. In the event that your video card runs out of system memory, it will resort to using system memory.

However, unlike most integrated GPUs where system resources are statically assigned to it, this is dynamic, so that the video card won't use your system memory until it has to, meaning that when you start your computer, all 2 gigs of your memory is free to use by the OS.