I sugest it is time to get a graphics (Video) card, asuming your PC will work with one. I sugest an Nvidea GT220 like mine (see below). It works well for me and uses very little power. I suspect any more powerful card is going to require more power then your supply can supply. Do you know the power rating of your supply?
By the way, a GT220 will likely cost no more than $50 (US).
By the way, a GT220 will likely cost no more than $50 (US).