Sumvision Sempra WAV file will not play on PC

[Vimes]

Hello

I have bought a Sumvision Sempra 4GB MP4 player, along with a 2GB Mini-SD card.
http://www.thedvdforums.com/forums/s...d.php?t=472188
It seems to work great but I'm having a problem when I use the voice recorder. The recordings save fine and playback with no problem but when I copy them to my PC they will not play with any software player that I have tried, even though they are saved in a WAV format. I have all the codecs installed on my PC but I assumed that the files should be able to play, as they do on the Sumvision, with no problem..?

EDIT: I have found that VLC media player will work even though both WMP and Media player classic will not play the file.