Question I am experiencing an issue whilst attempting to carry out the PolyTune Classic firmware update on Windows 10. Every time I try, I receive an error stating that the "libusb0.dll" file could not be located despite following the update instructions to the letter. What is happening What can I do Answer The problem is due to Windows 10 driver signature enforcement. This blocks the update process by preventing access to the "libusb0.dll" file. Prior to installing PolyTune USB driver to your computer - installation of "libusb0.dll" - you will need to deactivate the Windows driver signature enforcement.. Please see here how to. Once you are done, install the PolyTune USB driver then run the PolyTune Classic drop-D firmware update. The firmware update files for both Windows & Mac are located here. Here is a video from Tore for the PolyTune update guide. The same issue seems to occur on Windows 8, and therefore you should follow the same procedure as described above. For further information please feel free to get in touch with Support.