[Moto G Q&A, Help & Troubleshooting] lhtrevisan:
I'm on a windows 7 x64 machine.

Installed minimal adb&fastoot v1.1.3 via .exe installer... I don't really remember from where I have downloaded it, got it months ago, trying to unbrick my hard bricked moto G 2014.

Tried your method reflashing bootloader 41.1A found here:

41.1A

It also returned no error upon installation, perhaps, no luck on installing twrp again.

Tried flashing stock again:

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash partition gpt.bin

target reported max download size of 536870912 bytes
sending 'partition' (32 KB)...
OKAY [ 0.050s]
writing 'partition'...
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 0.350s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash motoboot motoboot
.img
target reported max download size of 536870912 bytes
sending 'motoboot' (1953 KB)...
OKAY [ 0.130s]
writing 'motoboot'...
(bootloader) Motoboot: Preflash validation for tz
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 0.410s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash logo logo.bin
target reported max download size of 536870912 bytes
sending 'logo' (1060 KB)...
OKAY [ 0.120s]
writing 'logo'...
OKAY [ 0.080s]
finished. total time: 0.210s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash boot boot.img
target reported max download size of 536870912 bytes
sending 'boot' (10240 KB)...
OKAY [ 0.430s]
writing 'boot'...
OKAY [ 0.610s]
finished. total time: 1.050s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash recovery recovery
.img
target reported max download size of 536870912 bytes
sending 'recovery' (10240 KB)...
OKAY [ 0.430s]
writing 'recovery'...
OKAY [ 0.610s]
finished. total time: 1.040s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash system system.img
_sparsechunk.0
target reported max download size of 536870912 bytes
erasing 'system'...
(bootloader) Erase allowed in unlocked state
OKAY [ 0.040s]
sending 'system' (249379 KB)...
OKAY [ 8.242s]
writing 'system'...
OKAY [ 8.129s]
finished. total time: 16.411s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash system system.img
_sparsechunk.1
target reported max download size of 536870912 bytes
erasing 'system'...
(bootloader) Erase allowed in unlocked state
OKAY [ 0.050s]
sending 'system' (252566 KB)...
OKAY [ 8.329s]
writing 'system'...
OKAY [ 7.401s]
finished. total time: 15.780s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash system system.img
_sparsechunk.2
target reported max download size of 536870912 bytes
erasing 'system'...
(bootloader) Erase allowed in unlocked state
OKAY [ 0.060s]
sending 'system' (249711 KB)...
OKAY [ 8.219s]
writing 'system'...
OKAY [ 15.926s]
finished. total time: 24.205s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash modem NON-HLOS.bi
n
target reported max download size of 536870912 bytes
sending 'modem' (47152 KB)...
OKAY [ 1.600s]
writing 'modem'...
OKAY [ 0.760s]
finished. total time: 2.360s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot erase modemst1
erasing 'modemst1'...
OKAY [ 0.050s]
finished. total time: 0.050s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot erase modemst2
erasing 'modemst2'...
OKAY [ 0.060s]
finished. total time: 0.060s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot flash fsg fsg.mbn
target reported max download size of 536870912 bytes
sending 'fsg' (102 KB)...
OKAY [ 0.100s]
writing 'fsg'...
OKAY [ 3.185s]
finished. total time: 3.285s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot erase cache
******** Did you mean to fastboot format this partition?
erasing 'cache'...
OKAY [ 0.060s]
finished. total time: 0.060s

C:\Program Files (x86)\Minimal ADB and Fastboot>fastboot erase userdata
erasing 'userdata'...
OKAY [ 0.070s]
finished. total time: 0.070s

Now i'm getting "fails" on the beggining.