That’s really bad advice. I have been using codec packs for YEARS without problems. Just because you have some bad experiences with codecs doesn’t mean it’s OK to assume that that’s the source of someone’s problem especially when it’s clearly not the codec packs causing his problem.
1.) He had this problem before installing the codec packs.
2.) He solved the problem by replacing .dll files.
If the problem was the codec packs it wouldn’t have existed before the installation of a codec pack, and it wouldn’t have been solved by swapping .dll files.