Maybe you are thinking about Hibernation which does indeed power off the unit?
My laptop only powers off the screen(monitor) in standby mode. The unit continues to run & all lights are on. This occurs whether standby is activated manually or automatically. I am using Windows XP and have previously performed a "fresh"(raw) install which didn't correct the standby problem. I checked the "power options" in the control panel and all settings are appropriate. I also tried changing the "virtual memory" to "system-managed size" with no success. I have no knowledge of "system bios adjustments" but I am willing to learn if it is the only solution. Does anyone have a solution or suggestion.