the cmos checksum is invalid ----cmos reset ( 502 ) how do i reset bios back to default

[ella1722]

the cmos checksum is invalid -cmos reset 502 --this is happening every day i put my computer on ...i did a bios update ..i think thats when the problem started ...how do i reset bios back to default thanks

[Prométhée]

hi

https://support.hp.com/us-en/document/ish_4209641-3226345-16

CMOS Reset (502) The CMOS checksum is invalid

During the startup process, the system performs a checksum test of the BIOS. If the checksum is incorrect, the BIOS is assumed to be corrupt and the system installs a hidden copy of the BIOS to correct the problem, and the startup process continues. The following message displays for 15 seconds before the computer automatically reboots. You have the option of pressing enter to proceed without waiting 15 seconds.

To resolve the CMOS Reset Error (502), restore the BIOS.

1. Press enter to restart the PC.

2. If the error displays after restarting, try to restore the BIOS using a USB drive. For more information, see the "Recover the BIOS using a USB recovery drive" section of the following:

   • For desktop computers, go to HP Desktop PCs - Recovering the BIOS (Basic Input Output System).

   • For notebook computers, go to HP Notebook PCs - Recovering the BIOS (Basic Input Output System).

3. If restoring the BIOS fails, contact HP.