mpg/mpeg files won't play after installing codec packs

i’ve installed nimo, k-lite and divx packs and i don’t seem to have any problems playing movies with weird codecs but i’ve found that for some reason, files with .mpg or .mpeg now won’t play, but i tried uninstalling and re-installing all the packs, windows media player and even my virus software, any idea what the problem is and how to fix it?

Go through the previous threads man! This question has been answered many times!

i think u will find it actually hasn’t, all i can find is ppl asking about mpeg2 and recording codecs. whats more, it was originally there and now it isn’t, has another codec pack caused this problem?