alarm
alarm
The Windows 10 alarm can still function even when your PC is off, as long as it has a power source or is connected to a battery backup.
PCs lack this capability. Regarding sleep settings, it varies. Your device must have InstantGo enabled. From what I understand, only certain laptops and tablets using Windows support this feature. It's a hardware option that manufacturers like Dell and HP can implement. For better results, consider using a real alarm clock or smartphone.