The Elder Scrolls IV: Oblivion Expansions?

Hi, I am trying to figure out why my Oblivion expansions don't work. I have the game of the year edition, which includes both expansions. I installed both to my hard drive, yet they don't work. I have tried reinstalling them but that didn't help. When the starting screen comes up, a message says 'loading extra content' for a few seconds then dissappears. Yet no matter how long I wait in-game, nothing appears. Starting a new game doesn't help. I don't have xbox live and I never have. Can someone tell me what to do about this?