Sometime just after I launched a new emulator, for very first time I was trying to upload my apk, however I got "emulator: ERROR: the user data image is used by another emulator. aborting".
I launched a new emulator, and left it alone, several minutes later, DDMS showed "device offline".
I had to restart a new one, you know, minutes wasted.
It's really bothering that I keep getting this error and slowed down debugging.
How do I fix it?
Open android debug monitor window by
typing "monitor" command in cmd,
then select device in the monitor window,
click on down arrow as shown in the figure then just click on reset tab thats all you will get internet connection.