In the menu go to "Trace", select "Next Boot and Driver trace". A "Trace Repetitions" screen will appear, select "Ok" and Reboot.
Upon reboot, BootVis will automatically start, analyze and log your system's boot process. When it's done, in the menu go to "Trace" and select "Optimize System" and Reboot. This time when your system comes up, wait until you see the "Optimizing System" box appear, continue to wait until the process is complete.