I have an Acer Aspire 5112 with an ATI radeon X1600 video card. Is it possible to upgrade this card?
More aboutnotebook video card upgrade
It is not cost effective to upgrade a notebook GPU. They are hard to come by (if they are discrete), not sold in retail, are expensive and have to have been available for your model number of laptop. Best way to do it is upgrade to a new laptop.
If you want to gaming then get a desktop, laptop is not meant to be played...