If you wanna watch your WMV videos on a large screen, you may use the video-out of your graphics card (if it has one). Few standalone DVD players support WMV format, but you may use standalone devices like Apple TV to watch such videos.

Apple TV supports QT, MPEG-4 ASP/AVS so conversion from .WMV files is required. But other Digital Media Receivers like NetGear Digital Entertainer support WMV format.