mobile

sorry for my English
my task is to install Orginal OTA 5.1
I try to restore the Stock or Factory ROM

when downgrade bootloader from 1.57 to 1.44
it's stuck at 80% and this whats happen

before:
(bootloader) version: 0.5
(bootloader) version-bootloader: 1.57.0000
(bootloader) version-baseband: 4T.28.3218.04
(bootloader) version-cpld: None
(bootloader) version-microp: None
(bootloader) version-main: 6.09.401.111
(bootloader) version-misc: PVT SHIP S-OFF
(bootloader) serialno: xxxxxxxxxxxxxx
(bootloader) imei: xxxxxxxxxxxx
(bootloader) meid: 00000000000000
(bootloader) product: m7_u
(bootloader) platform: HBOOT-8064
(bootloader) modelid: PN0711000
(bootloader) cidnum: HTC__001
(bootloader) battery-status: good
(bootloader) battery-voltage: 4229mV
(bootloader) partition-layout: Generic
(bootloader) security: off
(bootloader) build-mode: SHIP
(bootloader) boot-mode: FASTBOOT
(bootloader) commitno-bootloader: dirty-6d8a0b9b
(bootloader) hbootpreupdate: 11
(bootloader) gencheckpt: 0

after
version-bootloader: 1.44
i can access to twrp
my computer not recognize the driver at bootloader
that mean no fastboot command and adb command
when i boot to OS all seem to be work accept Fastboot command
any idea how to inject the bootloader again?