Bootup

From Styleguide

bootup

Technical.

The initial startup sequence on a computer.

Boot acceptable on all references. Resetting a computer is sometimes called rebooting. Although a game system is a computer, avoid use of boot as synonym for starting up or restarting a game console. If the game freezes, simply restart the system;as opposed to: If the game freezes, reboot the system.

Also see: reset.