Me sale esto la primera vez:
C:\magic\sdk\android-sdk-windows\tools>adb devices
* daemon not running. starting it now *
* daemon started successfully *
List of devices attached
HT96XKF04774 device
si vuelvo a escribir adb devices esto:
C:\magic\sdk\android-sdk-windows\tools>adb devices
List of devices attached
HT96XKF04774 device