Well, first see if those files play in Mplayer on the PC. I highly doubt that they would be DRM free, so they probably need special software. If it works on Mplayer on the PC, then it should be fine.

Also, if Mplayer does not play .WMV, you can play and encode it with VLC so it does work with Mplayer. This is because Mplayer is the best player on the tablets, because the VNC port is not as good...