Ok, Follower.
I said something very wrong here.
http://www.arduino.cc/en/Guide/Windows
On the USB boards, the power source is selected by the jumper between the USB and power plugs. To power the board from the USB port (good for controlling low power devices like LEDs), place the jumper on the two pins closest to the USB plug. To power the board from an external power supply (6-12V), place the jumper on the two pins closest to the power plug. Either way, connect the board to a USB port on your computer.
I meant Arduino Power Selector. But since I'm not a USB board user, I make a mistake. Sorry for that.
But Ananjar cannot use the USB 3.3 volts as only source for Arduino (and relay), in this case.