I downgraded My Dell Inspiron 17 5767 form Windows 10 to Windows 8.1. After this the R7 M455 is not working properly. After deinstalling the driver and tyring to reinstall the driver package for the M4xx whch is supported by Windows 8.1 64 bit, I can't install the driver. It is not displayed as an option in he installation menu. Is the R7 M455 only working under Windows 10?