The uninstallation of the plug-in should theoretically do it. You can try the 'DirectX plug-ins uninstaller' link on the links page. It may be possible to directly remove from the registry the plug-in entries but it may be hard (and dangerous) to find them, so the best way is: reinstall the plug-in, run n-Track, browse with the Windows explorer in the plug-in folder and drag its main file (usually with the .dll or .ax suffix) on the n-Track's window. A dialog box should now ask you if you want to run the self registration of the plug-in: if you click on NO, the program will launch the plug-in self-unregistration procedure, thus removing it from the plug-ins list.You can accomplish the same effect from a command prompt typing: "regsvr32.exe /u plugin_filename_with_path". This will launch the self-unregistering routine that should be in every plug-in. You may need to specify the exact path of regsvr32.exe (usually \WINDOWS\SYSTEM).