There are several synonyms for the phrase "starting computer." One of the most common is "booting up," which refers to the process of loading the computer's operating system. Another synonym is "logging in," which typically refers to the act of entering one's username and password to access a computer's features. Additionally, "firing up" can be used to describe the process of turning on a computer, while "waking up" is often used to describe the process of bringing a computer out of sleep or hibernation mode. Regardless of the specific phrase used, all of these terms describe the crucial process of getting a computer up and running.