how can i convert a 3gp video to wmv video?

I've had this problem before, I'm not sure it will work though this is if you have microsoft windows. First go to movie maker and then once your finish uploading/making your movie, on your left side you should see publish to and click on to your computer. Then you should see some options on converting your file and then click on WMV.

You find a video converter software to help you convert 3GP video to WMV video.
I always use Daniusoft Video Converter which could convert any video formats to other popular video formats in a good quality.
You can have a try.