ZeroPlusOne

I have been using switch for about 6 months and up to now haven't had a problem. All of a sudden when I go to convert from wave to mp3 files it gives me the message ACM codec file is not installed on this computer. I follow the instructions which lead me to the message that codec 1 is missing. Wen I try to find codec one the microsoft site just says "error". Can anone hel me? Thanks