UEFI BIOS Power On after Power Failure Option Greyed Out

[WST-IT]

We have the HP G2 SFF PCs with BIOS 2.36A.

After a power failure, all PCs turn themselves on.

The BIOS option to change this is grayed out. 

How could I possibly change this?

[DGroves]

don't know since HP has several model lines that use "G2" in their model/product name

if you provide the actual model line name, perhaps someone can help.

[WST-IT]

Sorry. ProDesk 600 G2 SFF

Product No. P1G87EA#ABH

[DGroves]

try a full cmos reset

remove pwr cord, press pwr on button for 5 sec

remove cmos battery, wait 15min  (note on side has a "+", make sure to reinstall the same way

reinstall cmos battery, connect power cord and power on then enter bios

if the reset of cmos was sucessful, you will have to set time/date (if date/time is allready correct, you did not reset the cmos)

now check pwr on after failure setting can it be changed?

[WST-IT · Accepted solution]

The solution was simpler: 'Power On From Keyboard Ports' should be disabled.

Although there is no warning about this setting, enabling it causes the system to always power on after a power outage.