Which uses less energy?

Shutting down your computer for an hour or two before turning it back on OR leaving it on for an hour or two set on sleep mode?

It's a common misconception that turning computers on and off adds to the wear and tear of the equipment and uses more energy than leaving the computer on indefinitely.
Computer equipment was made to be turned on and off. You will save energy by shutting it off completely, even if only for an hour or two.