If you have added more Vram to your gpu then you have broken it, you would have to dismantle and remove the existing vram and resolder the new chips on the board, so I think you are confusing Vram and System Ram up, System ram is installed on you motherboard and Vram is installed on your GPU, If you only have 4gb of system ram you can add more, but skyrim will not use more than 4GB of ram, the extra ram will make your os faster. Skyrim is a 32Bit Program and as a 32Bit program it will have those limits, there is nothing you or anybody will be able to do. Have you checked to see if the ram is the same as your other ram, mixing ram types and voltages can cause problems. what you should have done is use the money you spend and get a better GPU.