Media Player wont play video
Hello people, im new here in the Windows 7 thing, i'm totally amazed about the new OS, but i've had some problems about the WMP, it started cool, when all videos (MP4 included) could be played with WMP, but suddently, after, 3 weeks of usage on the OS, WMP does not plays video anymore, when i open a video on WMP all the playback screen shows black and the only thing i hear is the audio from video.
This issue has given me a lot of problems when using Sony Vegas 8 to edit videos, because now i can't convert videos with vegas and i cant add videos to edit. Also the thing that i can't watch videos on Windows Media Player.
This problem also occurred on my previous Windows 7 instalation (build 7000), problem that i've tried to solve with some codecs, but no good results though. WMP didn't worked at all.
I hope someone could help me because im very nervous, i work on video edition and this is giving me a lot of troubles.