Due to the way in which Windows 8.x handles system and device power states there may be some instances where a desktop or notebook computer cannot be remotely switched on by a "Wake on LAN" (WOL) command. The same model of system can be remotely switched on using WOL if the system is running Windows 7.
The Windows 8 Fast Boot feature also controls how the system is shutdown. The mode that Windows 8 uses to power down devices can leave the system not able to respond to WOL commands.
To resolve this problem, turn off Windows 8fast boot features.
Note:Further information can be found at the following link http://support.microsoft.com/kb/2776718