Microsoft had a tool called BootVis. It's not officially supported anymore, but you can still find it around the net.
From Fast Boot / Fast Resume Design:
The design goals for Windows XP on a
typical consumer PC are:
- Boot to a useable state in a total of 30 seconds
- Resume from Hibernate (S4) in a total of 20 seconds
- Resume from Standby (S3) in a total of 5 seconds
Boot and resume times are measured
from the time the power switch is
pressed to being able to start a
program from a desktop shortcut.
Bootvis.exe is a
performance tracing and visualization
tool that Microsoft designed to help
PC system designers and software
developers identify performance issues
for boot/resume timing while
developing new PC products or
Please note that
Bootvis.exe is not a tool that will
improve boot/resume performance for
end users. Contrary to some published
reports, Bootvis.exe cannot reduce or
alter a system's boot or resume
performance. The boot optimization
routines invoked by Bootvis.exe are
built into Windows XP. These routines
run automatically at pre-determined
times as part of the normal operation
of the operating system.
The Bootvis.exe tool is no longer available from this site.