Ok here is what it looks like when booted normally. There are two items in Device Manager I can see related to the Moto G:
The "adb devices" command lists the serial number as expected. I unplug the phone, power off, fast boot, choose recovery, and get the recovery menu. Reconnect usb, and choose the first menu item "apply update from sdcard". At this point I hear the USB device hot plug sound effect from Windows and return to Device Manager. Here is what is looks like:
unknown.png 87.92KB 14 downloads
But when I try to Update Drivers for this unknown device, no matter what category of driver I look at the message is always "Unable to find any drivers for this device". I tried specifying directly the folder containing the standard Google USB driver which comes with the SDK, but the result is the same.
I noticed that if I connect the USB cable while the fastboot menu is displayed, then the Motorola ADB Interface device is listed, but not the other one. And furthermore, even though it's listed in Device Manager, adb does not list it. Restarting adb server does not help.
I also tried adb reboot recovery instead of manually fastbooting to the recovery menu, but it still has the same problem with not recognizing the device in this mode. Argh.