Never have more than one codec pack installed. WMP plays most as they should be played - check Windows updates. Like whs notes, uninstall all extra codec packs, more than one codec may mess your system. VLC is quite safe, as it has the codecs in its own folder, not mixed with others. But I've had problems with it too, probably because of Windows updates.
There are various tools for codecs, simply search for "codec check" in your browser. I can't recommend any, though. And it's a jungle to go through!
As a footnote, to play Blu-ray, you need to purchase a program, since the codec is copyrighted by Sony, not available for free. A mere driver isn't enough.