Mplayer issues

When I open the multimedia file,the window of the mplayer appear first and disapper sooner,and the file can’t open.The mplayer can work last night.What’s worse,the banshee media player can’t work neither.I had tried to re-install the mplayer and the win32code,and that was helpless.
What can I do?Thanks

Try launching mplayer by itself first (not opening a file), and click on the configuration button (a wrench icon, I think?). Select the video tab, and try different video out drivers.