Audacity 2.1.3 File Exported to WAV Has No Sound

I have Windows 7 Professional and Audacity 2.1.3. I recorded a narration file in Audacity using a Plantronics Audio 655 DSP USB-connected headset (sound is OK), and exported it to a WAV (Microsoft) signed 16-BIT pcm file. When I open and play the file in Windows Media Player, the recorded audio cannot be heard. It is silent. I deleted Audacity 2.1.3, rebooted, reinstalled it, opened and exported the file again, and it still does not play the audio. The file plays OK in Windows Media Player but there is no sound. I’ve used Audacity (other version) in the past and this has never been a problem. Any ideas on how to fix this? I’ve spent way too much time on this including searching the forum for possible solutions.

Have you tried a known-good WAV file (or MP3, etc.) in Media Player to make sure something else isn’t messed-up with your computer?
Did you see a waveform in Audacity before exporting?
Did you play the file in Audacity before exporting?
When you open the WAV file in Audacity do you see a waveform or a flat line?