Hi,
In my case, I uninstalled the driver and re-connect the usb plug, then unknown device was appeared.
After that, I updated its driver and manually chose the "Altera USB-Blaster" (ver. 2.12.0.0), then it works fine.
"windows trying to load the original Altera driver (which does not expose a composite interface).
Fix: uninstall the original driver before plugging in the board"