hi,I am a kid of 12 years and trying to build...things with arduino uno r3 it was working properly while I am experimenting but suddenly a little bit of smoke came from somewhere and windows 7 displayed a message on the screen that the usb device which was connected to my board is malfunctioned .I connected my arduino to all the usb ports in my computer's cpu but it was saying the same thing .Then I went to device manager and saw there was a file named unknown device in universal serial bus controllers.I clicked on that looking for the properties and there I saw line like..."windows has detected problems in this device and has stopped it(code 43).
can you please help me ...I am waiting for your reply.
thanks 