Mac users are not able to save videos in .WMV format by default however there are applications which allow you to convert your video quickly and easily. 

One applications which is available in the Apple Store is called Total Video Converter Lite, you don't need to pay for the full version as the lite version should work just fine for this purpose.

Once you have installed Total Video Converter Lite you simply need to drag your .MOV video into the window. Once you've done that you will be presented with a window asking which format to convert to, select WMV. Your .WMV video should now appear on your Mac Desktop.