wavread function windows sound recorder

 i racorded some audio files in my computer and am using the wavread function.

the sound recorder in my computer saves the audio file in .wma format.

 using cmd i copied the same file as .wav

but still the wavread commamd is giving errors as ' not a wav file"

some years before i have done some work on speech but i do not remember the software i used to record audio.

 please help.
thank you