Changes in hardware or software. The file may have been installed, signed incorrectly or corrupted, or it may be malware from an unknown source.
The slave device is installed on x64? Attempting to install an unsigned driver on your computer will issue a warning. (Simply put, the driver has not been certified by Microsoft WHQL)
Solution:
1. Uninstall the original driver and try to reinstall it. Replace other drivers and find certified drivers in official website.
2. Download the killing software to thoroughly kill and detect whether it is caused by malicious software or virus.
3. Replace the system (XP or other version, try to reinstall).
4. Control Panel-System-Advanced System Settings-Hardware-Driver Signature-Select Yes to perform this operation automatically.