After completion:
reset
Then power off, remove the CMOS battery for 30 seconds, or short the CMOS clear jumper.
HP released the last "Critical" BIOS updates for the 840 G1 as late as 2021–2022. If you are running a version from 2015, you are missing three key improvements:
If your 840 G1 is currently on a BIOS version older than v1.36 (released 2016), you cannot jump directly to v1.52. HP introduced a new cryptographic signing key in 2018. 844g1 firmware update top
The Fix: You must install an intermediate version (e.g., v1.44) first, reboot, then install the latest v1.52. If you skip this, the update will hang at "25% - Updating Boot Block."
A: Yes, but only if the recovery BIOS is writable. Some dual-BIOS systems lock the backup chip. Still follow the same precautions.
Assuming you have fpt.efi (Intel Flash Programming Tool) and 844G1_update.bin: After completion:
reset
fpt.efi -f 844G1_update.bin -bios
Wait for the progress bar to reach 100%. Do not interrupt!
A: Some OEMs provide a Windows flasher (e.g., WinFlash). However, the top recommendation is EFI Shell because Windows background processes can interrupt the flash.
Best for: Bricked devices or Linux users. Then power off, remove the CMOS battery for
Type:
map -r
fs0:
(If fs0 doesn't contain your files, try fs1: or fs2:)