Windows 7: Unable to see movie in Media Player now? What happen?

I have never had any issues playing movies on my PC with the windows media player untill yesturday as I was fooling around with another program. I had installed the software mymovies.dk which updated all information in my movie library (actors,details, ect) for my WMC which is great and recommed.

It was all working great, up until I decided to rename all my movies VTS files too .mpg as some I read in some sites exaple: vts_01.MPG in order to see if my Xbox360 Extender might pick them up. Now all I get is "unknow dvd" and a black screen with no movie to see on my PC, seems like it wont upload it. I tried reversing back to its original renaming and still my windows media player wont play, also making it unplayable in my WMC =( but I did notice that my Cyber DVD software does play it with out an issue regardless of the renames.

Any ideas on what I can do to bring back my windows media player as the main movie player again?

I know its not a codec issue as it still plays inserted dvd's on media player, I fear that by trying to make things better I done them worst.