Vostro 1710 Graphics performance

Hi,

I have a Vostro 1710 which has only really been used for Internet/Mail/Documents. Now we want to play a kids game, Skylanders, which needs beefier graphics.

Is there anythings I can to upgrade the graphics memory from 338MB to a minimum of 512MB?

I seem to have all the other pre-reqs for the game;

Intel Core 2 Duo 1.86GHz - I have Interl Core 2 Duo 2Ghz

2GB RAM - I have 2GB

11GB HDD free space - I've got buckets load as I use a NAS for storage

Windows XP/Vista/7 - I have Windows 7

DirectX 9.0c - I have DirectX 11

Video card must be DirectX Compatible 512MB 3D Graphics Accel. - According to dxdiag I have Direct 3D Acceleration enabled but only 338MB

It's this last bit which tells me that I have all the pre-reqs except the required Memory on my graphics card and the graphics performance on the game is extremely poor. Any advice on how to speed up the graphics gratefully received.  Can't afford a new laptop (Can you hear the someone crying.......?)

Thanks,

Ian