The copy protection on the WTV files is tied in with your Windows installation. If you try to copy them to another computer they will not work. The conversion really needs to be done on the Windows PC.
You should refer to the question How do I convert WTV (and DVR-MS) files into a smaller standard format?. There are answers there that refer to using only the open source ffmpeg (disclosure: one is mine) and it is not necessary to use a Windows-specific program.