Quick Lesson:
Media files on a computer operate under the relationship between CODECS and CONTAINERS.
Codecs are the actual techniques in which something is encoded and then decoded (playback). So, h.264, DTS, MPEG Layer 3, MPEG 2, etc are all CODECS.
A Container, on the other hand, is the actual file you interact with. So, MP4, MP3, WAV, MKV, AVI, etc These have nearly NO baring on what kind of information is stored inside. A container is exactly what it sounds like: it's a file that contains data from codec encoding and some header data describing them. There are some restrictions in the container standards and definitions that say this or that codec cannot be used, or these settings can't be used, it's up to the container.
So, just because you have a MP4 container ... doesn't mean it's video is h.264.
With that being said, WAV is a very basic container, it usually holds RAW or MPEG 1 audio.
What you need to do is figure out what's inside the WAV container. You can use something like GSpot (very iffy, it barely works for me) or FFMPEG (command line, sorry, but it's the best tool out there) Which can not only tell you what's in it, but the properties of it and even allow you to manipulate it (like pull it out of the container, convert it, etc)
You can also just play the file, even though it's not playing, depending on the player, you may still be able to look at the header information. If you use something like Media Player Classic (NOT TO BE CONFUSED WITH WINDOWS MEDIA PLAYER) you can go to properties and get this information (Very useful)
I'll leave the searching up to you to find these things, as they're very popular. There's a lot of information out there on using FFMPEG command line depending on what you want.
Just try to see if the codecs being used on the data in the container ... exist on your computer. If they don't ... hop on over to Free-codec.com and get the specific codec you need ... not some massive collection pack (though you should leave the other codecs you have alone).
I wish I could remember this one tool for Windows ... it listed all codecs installed all sorts of stuff, was very useful ... but I can't remember it's name.
Blame it on Microsoft, God does.