some useful info i came across as to how to use bootvis the correct way :
BootVis - Download
BootVis is a boot performance trace visualization and optimization tool. This tool invokes the built-in Windows XP boot time optimization process when you run it, instead of waiting for it to be scheduled by Windows (roughly every three days and after the system has been idle 10 minutes). You will notice immediate improvement in boot performance for this reason. It is not necessary to run BootVis again unless something has been added or removed from the boot sequence (Drivers, Startup Applications ect...)
Instructions :
Download and Run. In the menu go to "Trace", select "Next Boot and Driver Delays". 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.
Notes - BootVis requires the following services be enabled and the system rebooted before using the "Optimize System" function:
- Task Scheduler - Automatic
- COM+ Event System - Automatic
Here