Corrupted download mode or hardware issue. Fix: Try a different phone (to rule out hardware). Reinstall the driver after a clean boot.
Are you trying to with a specific device, or are you looking for a download link for this driver?
to see if the device appears under "Ports (COM & LPT)" or "Universal Serial Bus controllers" without a yellow warning sign. Are you having trouble installing this specific driver, or are you looking for a download link from a particular manufacturer? How to Install USB Devices under Windows 10 and Windows 8
Always ensure you download such drivers from (like GSM-Forum) or official support pages for your specific device. Unverified .exe or .sys files from unknown sources can contain malware or cause system instability.
Conflicting driver from a previous installation. Fix: Open Device Manager, right-click the failed driver > Uninstall device > Check "Delete driver software". Then reinstall Jungo v4 fresh.