Problems with Mpeg 2 codec

I am having a problem with my codecs. I have Intervideo on my system and it plays all mpg files with no problem. When i try to use real player or windows media it is telling me that the needed codecs do not exist. Obviously they are on my system if Intervideo can play the file. How do I correct this?

i am having trouble too.

How many Mpeg related codes are around just not
to be compatibel with Windows-media-player. is there a program that synchronyze these problem so it can be solved practically

Which mpeg converter is know around to
be complete toolbox for the job
is still coming from the market