Does the Power Button interact with the OS when I do force shutdown?

zinco · January 21

When I press and hold the power button on the case, does it interact with the OS, or does it force shutdown automatically?
Similar with other buttons (restart/etc.) as well, because I once got my PC in a situation where it crashed and everything froze. At that point when resulted in a force shutdown, it didn't work (i had to turn it off by the PSU). It wasn't any problem with the button, it worked afterwards, but that got me wondering. I couldn't find anything on google either, so does anyone here know? I'm talking about Windows btw.

BlueChinchillaEatingDorito · January 21

38 minutes ago, zinco said:

When I press and hold the power button on the case, does it interact with the OS, or does it force shutdown automatically?
Similar with other buttons (restart/etc.) as well, because I once got my PC in a situation where it crashed and everything froze. At that point when resulted in a force shutdown, it didn't work (i had to turn it off by the PSU). It wasn't any problem with the button, it worked afterwards, but that got me wondering. I couldn't find anything on google either, so does anyone here know? I'm talking about Windows btw.

Only when you press and release the power button quickly will it interact with the OS to do a graceful shutdown. And that is if it's configured within the OS to do so.

If you press and hold, the system board will simply just power off for a forced shutdown. When you boot back into the OS and look at the system logs, it'll report it was an unexpected shutdown.

zinco · January 21

thanks for the detailed post. i also need to know if that long press is monitored via the BIOS or some other software, or if its purely hardware?

Eigenvektor · January 21

17 minutes ago, zinco said:

thanks for the detailed post. i also need to know if that long press is monitored via the BIOS or some other software, or if its purely hardware?

This is handled by the motherboard's firmware, afaik.

If you press and release, the firmware sends an ACPI signal. The OS can interpret that signal and perform a regular shutdown, go to sleep, suspend (or ignore it, if configured to do so). If you hold the button, the firmware will simply cut power at some point.