1st:
why do you wanna update the BIOS? Is there a different problem with the laptop?
2nd:
which program do you use to update the BIOS and which version are you using (Bios and tool)
which BIOS version is currently installed?
did you disable secure boot?
-> Go to the Security tab and set the „Secure Boot“ setting to „Disabled“.
From which to which CPU do you wanna upgrade to?
did you get the CD burned to boot from it?