Hi Charlie.
I am not giving you a solution. However, I believe that you are using
Microsoft Office 2000 or below, that is why you need to convert the
music files; as Microsoft Office 2000 did not support for inputting
MP3s or other extensions. When you convert music files, usually MP3 to
WAV, which you have done, the resulting file size will be greater. In
order to input MP3s (or ~~MAYBE~~ other extensions) to a PowerPoint
Presentation, you need to have Microsft Office XP (XP = 2002), note
that it is only for Windows XP users, but if you are not using Windows
XP, you ~~MAY~~ purchase Microsoft Office 2003, I am not so sure about
what operating system does it supports, hence check it out if you want.
Good luck!
**I will not be responsible for any false facts or loses, thank you!