https://support.microsoft.com/en-us/help/316992/file-types-supported-by-windows-media-player

Similar to the AVI and ASF format, WAV is only a file container. Audio content that is compressed with a wide variety of codecs and that is stored in a .wav file can be played back in Windows Media Player if the appropriate codecs are installed on the computer. The most common audio codecs that are used in .wav files include Microsoft Adaptive Differential Pulse Code Modulation (MS ADPCM) and uncompressed Pulse Code Modulation (PCM).

My guess - W7 lacks a codec for whatever LP Recorder is using it its wav files, probably plain old uncompressed PCM. It that's true I expect W10 won't play it either.

Try searching for, and downloading, a PCM codec.