Q:
A: Ive seen this question a few thousand times. The answer to the question is variable--meaning that it is better for your hard drive to stay running all the time rather than to continue stopping and starting the disk each time you boot and shutdown. In terms of the power supply unit and fans and such most of those are given of a life of like 50000 hours or something similar to that so it may be better to shut your computer off when your done in terms of the powersupply and fans and such.