Windows XP has the ability to trace boot and resume metrics, and to dump the resulting information to a binary file viewable through Bootvis.exe and other tools. Bootvis.exe displays various time-interlocked graphs showing such things as CPU Usage, Disk I/O, Driver Delays and resume activity.
Bootvis.exe can show many types of useful details; the best way to start is by dragging an area on the graph and either double-clicking it or right-clicking to use the context menu to see what options are available. The operating system instrumentation starts about one second after the boot loader loads.
Overall boot time shown in Bootvis.exe should add BIOS power-on self test (POST) time + one second. Taking boot traces with Driver Delays will lengthen boot by two to three seconds. The resulting binary file will be several megabytes in size.