How do I uninstall BitTorrent Mainline?
If you allowed BitTorrent Mainline to create an uninstall entry in the Windows Registry during the initial installation dialog, then all you need to do is uninstall it from the “Add or Remove Programs” applet in the Control Panel. Otherwise, you can simply delete the BitTorrent Mainline executable file from wherever it is stored. If you are concerned about the settings being left behind on your computer, delete your entire settings directory as well.