Pretty much every motherboard supports the “wake on lan” feature. This allows a network signal called a “magic packet” to boot the target computer from another computer on the LAN. If you have (or support) multiple computers it can be a lifesaver; or at least a nifty way to save power. All it requires is you know the MAC address of the target machine.

Try using this applet to boot your computer remotely:
www.moldaner.de/wakeonlan/wakeonlan.html