Are you wanting the machine where wol.exe is execute to wake another machine? Or do you want it to wake itself?
If the machine you are trying to wake is itself, that will not work because it is already asleep. So it will never get the command, because it is asleep.
If you are trying to send the command to another machine it should work, as long as the device supports WOL and WOL is turned on in the BIOS (if using a PC or what not).