Oops 
JARGON ALERT! A cold boot is a relatively ancient term, so ancient that only an old timers like me or a computer engineer is likely to apprehend its meaning.
There is no Cold Boot menu option. A Cold Boot is initiated by pressing and holding the Power button until the computer completely powers down. Pausing several seconds then pressing the power button again to turn the power back on and boot the machine. (
NOTE: The power down process is different on iOS devices, but the concept is the same.
Cold Boot (a.k.a.
Hard Boot) where the power to the system is physically turned off and back on again, causing an initial boot of the machine. In other words the computer is completely shut down for a period of at least several seconds to allow the capacitors in the CPU to drain their electric charge and thereby
completely erase
ALL the hardware registers.
In modern computers, most situations can be cleared with a
Warm Boot (a.k.a.
Soft Boot, Reboot, or Restart which is under control of the Operating System and may not clear all of the hardware
registers but in rare cases a Cold Boot may be necessary.
