How can I stop QuickTime from opening WMV embeds?
Click on a .wmv file once, to select it

Then click Command + I (That's the Command key and the letter i key at the same time)

In the resulting dialog box, click the Open With arrow

In the pulldown menu select the app you wish to use to open .wmv

Click the Change All button to force all .wmv files to be opened with your selected application

You're done