I suggest that included in the mIRC help file and/or on the mIRC website(as well as IRC network websites), and also AV websites, taht users be made aware how to disarm these trojans themselves.

This part of mIRC's web page has a good bit of info and related links, like to an area of Symantec's website with how to remove details. As does this thread
Wandering about in the registry can be dangerous for new users who need to understand it has to be done carefully and to make a backup first.