If you need to turn your PC off and then turn it back on again, it is best to wait at least 30 seconds before hitting the power button again. The reason for this is to allow your hard drives time to spin down and park their read/write heads before they receive their wake-up jolt. Doing so will increase the lifespan of your hard drives.

On the general subject of powering on and off, it is best to leave your PC on for longer time periods. If you need to use your PC several times throughout the day, leave it on all day rather than turning it on and off each time. This will avoid the cooldown/heating of the PC’s hardware and prolong the lifespan.