Your best bet is likely a freeware on one of those two sites. You can find programs on the big download sites but I've found often that if they are applications I haven seen on videohelp especially, that they work in some cases but at other times can output video with the wrong aspect ratio. Or they may lock you in to "convert and burn in one shot" which isn't a good idea unless you have a lot of experience with a program and know it will almost always produce a good result.
Also you may want to check out AviSynth since it it used by many freeware tools to convert the input of just about anything you can play. The forums on videohelp are a good resource.
I haven't done much with wmv. I think the programs that output to it are limited because it's a Microsoft proprietary format if I remember ight. I've been away from video conversion for a couple of years. But check the freeware first. Some are much better than the commercial programs(if not talking professional software costing thousands that is.)