My computer was switching on itself so I open my computer to see if there was any wire problem. I even removed the usb prots and when I reconnected it I connected it from the wrongside and again I connected them as it has to be. Now my both frontal and back side usb ports are not working. They do not recognise my pen drives but when I connected my mobile to it then it recognizes it. I checked in the Device manager and they seem to be fine. Also I have checked in the BIOS there also it is enabled. Please help. Is it harware problem or any software problem.