I cannot play games anymore? :(?

So today I tried to play civ IV Complete edition. It loads the first page then I click play and nothing happens besides that screen going away. I have already checked my ram. I have plenty of space on my harddrive too. (4gb ram & 500 gb harddrive) I have a HP pavillion with windows vista home premium and an intel pentium dual core processor. Music cd's work fine and none of my other games will play either. Your help is appreciated!