PROBLEM! USB NOT FOUND!! HELP!!

Hi everyone,
I'm doing a robot for school project,
Im using an Arduino UNO but my computer doesn't reconise the card anymore!
It was working perfectly but out of the blue it stoped.
I trying everything, I changed the cable, changed computer.
The PWR Led turns on, the RX/TX Leds flicker shortly and my program seems to boot. But the board is no longer found by my computer (Win7). =(

What's wrong with my arduino and can I fix it?

Thanks

I just had this problem but with XP.
I fixed it by disabling then enabling COM3 from the device manager.

In case that makes no sense, here is a walkthrough :

  • Go to Windows Control Panel -> System -> (Hardware Tab) Device Manager
  • Scroll down to and open the Ports tab
  • Right click on COM3
  • Click DISABLE
  • Wait for the window to update
  • Right click on COM3
  • Click ENABLE

Quit the Arduino IDE and reload. It may have defaulted to COM1, so make sure you click on Tools -> Serial Port and select COM3 before trying to upload to your board.

Thats my first post here - I hope it helps :slight_smile: