Solution: You must run the installer as Administrator. Also, disable antivirus real-time protection temporarily (some AVs block filter driver installation).
Solution: Filter driver version mismatch. Uninstall the filter and use Zadig’s “Replace Driver” with WinUSB instead of the legacy filter. libusb-win64 filter installer
Legacy (libusb-win32 / libusb-win64 inf_wizard / filter installer): Solution: You must run the installer as Administrator
libusbK or vendor packages: sometimes provided as installer executables (libusbK installer) which place libusbK.sys + libusbK DLLs. libusbK or vendor packages: sometimes provided as installer
Notes:
A filter driver sits in the device stack, intercepting I/O requests. The libusb-win64 filter installer does not replace your existing driver (e.g., a serial port driver for an Arduino). Instead, it inserts a lower filter that allows WinUSB/libusb to coexist. This is critical for devices that need to be programmable (via libusb) but also function as standard HID or COM devices.
If you are trying to get a device (like a controller, flasher, or radio dongle) working with specific software and the filter installer isn't working, the modern standard is usually Zadig.