Help!! How do i know if my arduino is broken?

i try putting an mp3 source connected into my arduino using the usb not the ext...

the problem is after that my computer does not recognize my arduino and i cant upload any files anymore ...

still the led and reset function is still working...

help me this one pls... i try looking for the device manager and its says that the usb does not recognize...

how to re install the arduino?

misoke: i try putting an mp3 source connected into my arduino using the usb not the ext...

You did what?

i use the mp3 power supply connected to my usb printer then to arduino usb slot...

That makes it even less clear.

misoke: i use the mp3 power supply connected to my usb printer then to arduino usb slot...

Can you draw a diagram? You have a MP3 power supply (whatever that is exactly) and you connected it to a USB printer and then (how?) into the Arduino.

Can you tell use more about this MP3 power supply? MP3 is a form of music file storage. In what way is there an MP3 power supply? And how did you connect it to your USB printer?