It would seem that your GPU is integrated to the motherboard (Intel GMA x4500). The maximum amount of dedicated memory seems to be 128Mb if I'm not mistaken, but it can share some of your RAM with the rest of the system. In any case, it won't really matter that much; You wouldn't be able to play most games even if you had 512Mb of dedicated memory for the GPU.
EDIT: Missed your last post before posting, That is exactly what it should say, and there is no way to increase the dedicated memory, but it wouldn't have much of an effect anyway since you already have some shared memory that the GPU can use.