If you are using our organizer Notesbrowser you should move the tool to the Notesbrowser Plugins folder and use it as a plugin (in Notesbrowser->Configuration->Plugins). Then you can launch DoNext with a right click in Notesbrowser and also it uses the Notesbrowser skins.
This tool is only one single file big. It creates only additional file 'ToDoList.xml' in the same folder to saves all settings and data. No entries are made into the registry.