The press and hold is part of the Advance Power config settings...
It should be a part of the bios, under advanced power settings. I have mine set on "press and hold 4 seconds" cuz my dog hits my computer alot. You can set the power button to do alot.
Windows also has these settings as well...
I think it's the bios settings because Windows is pretty much gone by the time the "It's safe to Turn Off" screen comes up. Check for ACPI (I think that's what it'll be called)