This will only work if your computer supports this. For this, both your BIOS and your OS/2 must support at least Advanced Power Management (APM) V1.1. The APM level of your system (and the APM.SYS driver level version) is displayed on the shutdown settings page for your convenience.
If the "Delay" setting is also enabled, XShutdown will wait three seconds
before actually issuing the power-off request to the APM.SYS driver. This might
help on a few systems where the APM driver switched off the power before all caches
were flushed. If you get CHKDSK's after using APM power-off, you might want to
try to enable this setting.