If you leave your computer at home or work when you go out, this consumes additional electricity. Instead of doing so, you may remotely turn on your PC whenever you need to use it. This way you can save some money and energy.
During the software installation process, you need to choose if you want to be able to power up your computer remotely or via Wake-on-LAN (WOL). The two options should be enabled if you use them, but they may also turn out to be unnecessary for your needs.

What Is WOL?

This technology is used when a device connected to a network wakes up other devices on that same network. This method does not consume much electricity and it provides easy access to computers and servers in remote locations. It enables programmers and system administrators to start, shut down and monitor PCs without being at their physical location. 
You can easily start up your PC even if you are not at home or work. However, this is possible only with WOL-capable computers. If your PC supports this option, you will need to enable it in the BIOS settings (it is disabled by default).
 Nirsoft WakeMeOnLan can be used to schedule on/off times for your computer. It also allows you to view the present power state of all PCs which are currently on the network, switch them off or wake them up. This tool is fully configurable and works on 32-bit and 64-bit versions of Windows XP/Vista/7/8.
Another useful and portable tool from NirSoft is WakeMeOnLan, which shows a list of computers on the network and allows you to turn one or more of them on with a single click. Scan the network using F5 to reveal all connected machines. To send the magic packet to a computer, check to see whether it's on first or add it manually from the File menu (Ctrl+N).