What player can play a .vob file?

I have downloaded the whole season 2 of dexter, its ah .vob file. I have watch it already using windows media player. But after a year when i try to watch it again WMP can't play it any more. The error says "Windows Media Player cannot play the DVD because the disc prohibits playback in your region of the world. You must obtain a disc that is intended for your geographic region." How did it happened?