I downloaded windows movie in Windows 7 but now my Outlook won’t play wav files and I get this “Windows Media Player encountered a problem while playing the file.”

I downloaded Windows Movie Maker in Windows 7 but now in my Office 360 Outlook I can't play wav files and I get this "Windows Media Player encountered a problem while playing the file." Worked great before downloading Windows Movie Maker through Windows Essentials. How do I fix it or perhaps go back to where I was. Windows Movie Maker just sounded like a nice idea, but I hate it now.