WMP wont play MP3 file

I am baffled. I recorded my voice using AUDACITY version 1.3 beta at home, and exported to an MP3 file using their LAME conversion plugin utility. I was able to play the MP3 file at home using the Windows Media Player (win7). However, the WMP at my office opened the file and played through it without complaints but produced only the "sounds of silence". I have windows XP at the office. Could it be that the Windows Media Player at my office needs to be updated to be able to play MP3 files? I thought it would have given me an error message if it was not capable of playing MP3.

 

I did rule out the trivial problems. Speaker was working and WMP was able to play other files. The file was identical -- I played it directly from the flash drive on both computers. Even worse, I also gave it to another person at the office, and his XP system would also play it soundlessly. YET the identical file plays perfectly well at home on my WIN 7 system.

 

It probably used a codec that XP doesn't have. You can download GSpot to see what codec is needed, and test if XP has any that will play it. Compare it to an MP3 that does play.