Hi Whiper,
Welcome to the forum.
Firstly, please make sure you have
installed the following firstly:
Uninstall the version you have installed on your computer at the moment. Now, I would suggest you download the
MTV Convert Tool 3.06 (MP3 Player Utilities 3.06) from our site
here instead and install it.
Once you install it, try converting to .MTV again and let me know what happens - whether it works or not.
Also, can you tell me what file type you are trying to convert into an .MTV please?