Plus does seem to actually support playing WMA files for notifications. Just enter the file name in the when choosing a sound and continue setting up the notification as normal.
It won't allow you to preview it ("This sound cannot be played by Messenger Plus!") but I've just tested it and confirmed it worked on 2 WMA sounds that I tried (using Messenger Plus! Live 4.50.0.312).
Hope this helps
Also, according to Wikipedia:
quote:
Originally posted by Wikipedia
to force Sound Recorder to save as WAV, the user must start Sound Recorder with the command line "soundrecorder /file outputfile.wav".
So this could be a possible solution too.