Originally Posted by
StuckInYYZ
This varies with the manufacturer. UPSs are often shipped with the terminals disconnected or taped up. Many smaller devices with batteries often have them pre-installed but with something to break the circuit. I'm unaware of any "software" that would prevent a laptop from turning on. If anything, it's a matter of making sure the power button is unlikely to be pressed.
For my laptop in question, there's an option in the BIOS that will prevent it from being turned on until it's plugged in. The setting is supposed to be used before maintenance of the laptop, but it's also sent from the factory in the same way. So you'd need to plug it in before it can be turned on for the first time. The power button was next to the keyboard so it shouldn't get pressed anyways with the screen closed.
Regardless of the precautions, I think it's easier for airlines to have a blanket rule of no electronics, rather than some sort of complicated conditions that you're leaving self serve bag tag kiosks or agents to ask about.