ok first solution might sound simple but try a different usb port
next, i suggest you go into the device manager and make sure that you do not see this symbol first
if you do see that then right click on it and select uninstall and restart your computer.
if that doesnt work and you are using a desktop machine shut down the computer and uplug the power cable for about 5 mins, if laptop then shutdown and remove battery then power back on.
best of luck