[Moto G 2015 General] ResistanceIsFutile:
Trying to Aid

I'm only listing some copy and paste information for you, which might be helpful or not. It's the only aid of info. I can offer you to sorting this out

To help others here or elsewhere you'd ask of XDA's helping you, some details - Please / it's extremely difficult to troubleshoot - given all of Windows versions.

ADB requires that multiple processes, hardware, and drivers function properly, it may simply be a driver issue, but who's to know.

What PC OS version are you using?

Which ADB version was downloaded and where did you install ADB on your PC, - there are several now available in options to download and install.

[Minimal ADB and Fastboot tools / 15 seconds ADB TOOLs / Android SDK Tools / etc.]

Have you tried to run ADB in command prompt with Run as Administrator to running the file? Is the right directory recognized in command prompt and ADB being found?

There is a good chance that Windows 10 is causing the issue - if it's your OS used.

Did you try to disable Driver Signature Enforcement before installing the driver?

"Windows 10: Press the keyboard shortcut Windows key + I to open the Settings menu, then go to Update and Security > Recovery. Under Advanced Startup, click Restart Now.

On the reboot screen, choose Troubleshoot > Advanced options > Startup Settings > Restart. You’ll find yourself on the Startup Settings screen. Here, choose option number 7: Disabled driver signature enforcement."

Do you see any errors in Device Manager of PC - showing exclamation mark / "device not working correctly"?

Do you get any notifications once you connect your phone to the computer? For example, you might get the option to connect via MTP (media transfer protocol) or another option. Some phones do not initiate an ADB capable connection by default. They load MTP or something similar. The trick is that some phones can connect only over the photo transfer protocol. It doesn't make any sense, but that might solve your problem.

After installing an Android device driver on your PC have you done a PC restart, plugged in the devices USB cable after such a restart and seen your device recognized?

Have you tried other Android Device drivers - Koush's universal ADB driver - Google USB driver?

That Koush's universal driver and/or any manual android device driver installation/update may need to be tried to get your device recognized in your PC. (see info. given in the links).

http://www.makeuseof.com/tag/android-wont-connect-windows-adb-fix-it-three-steps/

https://www.recovery-android.com/install-android-usb-driver-on-computer.html

http://visualgdb.com/KB/usbdebug-manual/

https://xdaforums.com/showthread.php?t=1413293

http://android.stackexchange.com/questions/106702/how-to-install-adb-fastboot-in-cmd-with-usb-drivers

All covered links are to the same general concepts and may or may not be helpful.

Do you have a many of ADB drivers/Android Device Drivers installed and conflicting with each other?

Have you tried uninstalling the driver(s) (all other android drivers) and reinstalling just one with a PC reboot?

If no android device is detected that's an issue with the operating system. (Automatically diagnose and fix Windows USB problems).

https://support.microsoft.com/en-us/help/17614/automatically-diagnose-and-fix-windows-usb-problems

http://www.nirsoft.net/utils/usb_devices_view.html

The USB cable could be another area to look into - is it a factory or after market one being used. USB-cable that can only carry a charging current, so not to being of a data compatible option. Try different ones you have then and see.

Charging cables are among the most common cause of ADB failure.

As I've tried to indicate all of this may or may not be useful - just something of a contexts to look at and decide for yourself or anyone with similar problems. :)