Holy stuff, you're completely handicapped. The LE means "Light Edition", so it's not even as good as a normal card. It's a terrible card and will not run these games very well on low. I googled your card + those games in an effort to help you. Some people have had success running it at all the lowest settings. But they all had dual cores clocked at 3.0 GHz, and still had massive lag spikes when running around outside in Oblivion. I'm telling you right now, to save you money, don't buy those games until you have a better card.
You're no doubt going to ignore me. Despite the fact that I posted all relevant information showing that your card isn't nearly as good as the minimum required card.
Good luck.