Vram is 256 mb but dedicated is 64 mb and shared is 192mb . how do i change it.. no option in bios also. Sony vgn n220e

You should not change this. Laptops have small video chips and often depend on "shared" memory to achieve good performance without overheating. Basically, the video processor borrows some of your installed RAM memory. Also, your laptop may have been supplied to you with less total RAM memory than the maximum and you can add more memory. In Windows, click on Start then right-click on Computer and select Properties. In the Properties window you can read how much total memory is installed. 2GB (2048MB) is a desrirable amount for Windows XP. Windows Vista and Windows 7 can benefit by having total 4GB of RAM memory. Check your Sony user manual for instructions on adding more memory. Basically, you turn off the laptop, remove the battery pack and unscrew a small cover on the bottom of the laptop to access the memory slots. Usually, there are 2 slots here. Ideally, you should install a matched pair of memory modules (a "kit") for peak performance. However, quantity of memory is more important than having matched modules, so if one slot is occupied and the other slot is empty you may simply buy one more module and install it in the empty slot.