power surge on the usb port . unknown USB device needs more power than the port can supply. i purchase it only 10 days .but after plugin my pen drive the message repeatedly come at same time my webcame also not working
i think you the laptop might have been damaged. This usually happens when a higher power rated device is placed in you usb.
usually a usb 3.0 can give till 900mA , So please keep it in mind while using devices.
Most likely your Webcam has been affected ( ive seen webcams being affected first when you mess with the usb ports)