Easy fix, dont get down just yet ;-)
Download the file from here and put it on the root of your sd card
Open up the zip and extract the Recovery.img to the folder with adb and fastboot. Turn your phone on by holding Volume UP/Power. Youll see FTM on your screen. Plug your phone in and open the command window like before. Type adb reboot-bootloader then fastboot boot recovery.img Your phone will boot to stock android recovery where you can install the update.zip and your phone will be out of the box new
I did what you said above.
1. got he update.zip and put to root directory. (use adb push to get it there)
2. extracted the Recovery.img and ran via adb reboot-bootloader and fastboot bot recovery.img. (Phone didn't reboot, had to do it manually).
3. install update.zip and got error:
assert failed: getprop("ro.product.name" == "zte_nex"
E:Error in /sdcard/update.zip
(status 7)
Installation aborted
I'm going to try to download the update.zip again and reload it but I have done it twice now and the same effect. Any other ideas?
BTW, I appreciate the help. You are dealing with a senior citizen who is an old mainframe programmer, so you will have to excuse the senior moments.

. slow upload speed. this will make your device completely stock again [NO ROOT]

