Arduino micro: no virtual COM port any more


when I connect my Arduino Micro to the computer, in device manager it first shows up as "Arduino Micro bootloader (COMx)" but then it does not switch as usual after some seconds to the normal "Arduino Micro (COMy)" but just vanishes. So I am not able to upload it with the Arduino IDE any more. I am using Win 8.1 and going back to a system restore point where it used to work fine did not solve the issue.
I am not sure if this behaviour happend after an unsuccessfull upload or if it is related to some other cause.

Any ideas for solving this issue are highly appreciated!


Finally I managed to solve this issue.
It was not related to the PC but to the Arduino Micro. Here is what helped:

  • Play around with the reset button till the Arduino IDE sees the temporary COM port. Quickly select it (Tools->Port)
  • Upload a basic sketch (I think I pressed and hold the reset button before uploading, as described in the Guide to Leonardo and Micro in the section "Uploading Code to the Leonardo and Micro" in case auto-reset is not working)

Now everythink is working fine again.

A similar issue was discussed in this forum under the title "Problem with Arduino Leonardo, the device is not recognized".