HELP! Game launch issues!

OK, so I installed this game on Thursday night, got to play it Thursday night, Friday, and Saturday no issues. Now today, when I launch the game I see the 2 promo screens all the way up to Gear Box, then on the next one it kicks me out and like minimizes the game, finishes loading (I can hear the music and claptrap and all) and when I click on the Icon to try and get into the game, it flashes up, and then rejects and takes me back to windows, with the game still running. I have not made any PC changes, no changes to graphics IN the game or to the graphics card or driver to the card.

I don’t know what is going on, basically, at this point the game is unplayable. I can’t play anymore, as I can’t get into the game. It loads, I hear the music, I hear claptrap, just can’t get it to stay full screen so I can access it to play it. HELP!!!