WMV or Windows Media Video is both a video codec and a video container developed by Microsoft. The file extension (.wmv) and the codec (wmv) both have the same name, which could potentially lead to confusion at times.
WMV is Microsoft's family of video codecs including WMV 7, WMV 8, and the newest, WMV 9. The WMV codec is competitive from both low resolution to HD quality as well.
Coconut's WMV video encoder will provide you with the best video quality for your project.