A computer system configured to authenticate a user and to power-up in response to a single action by the user is described. In particular, the computer system includes a user verification device which interacts with the user. In an embodiment, the user verification device includes a biometric sensor which captures biometric data from the user. The biometric data can be of any type. The user verification device is configured to capture biometric data in response to an action by the user desiring access to the computer system. The user verification device can have a button-shape for receiving the finger, thumb, or any other part of the user.