excel not working right

All of a sudden my Excel has stopped working correctly. When I turn it on a message  comes up that says Excel has run into an error and will have to close down. It gives me the option to repair now which I click on. Then the file opens with at least 8 files on the left side under the heading of document recovery .I'm supposed to click on the ones that I want to save. By this time the Excel window just closes on its own. Help