The LEDs (Light Emitting Diode) on your laptop are status indicators that show the operating status of your computer. Each of the status indicators is lit when the corresponding function is in operation.
If your laptop can turn on with the power led lgiht off, don't bother trying to fix it.
Programs that are loaded as the computer starts up remain active in memory. Consequently, they are one of the main causes of a slow boot into Windows. Disabling programs you don't often use from automatically loading up each time the computer powers on can decrease boot time.