Stuck on "Cannot connect to xbox live, try again later" screen

My xbox worked fine for the longest time, I never hooked it up to Internet or anything either. I just played normally. Then I started it up one day and it went to a "Couldn't connect to xbox live, please try again later" screen, or something like that. And I've tried pressing every button to go back to the menu or anything and nothing happens, it's really frustrating because I would love to play some of my old games.