[madpata]

Maybe has something to do with cached driver configuration, but I don't know which version of Windows introduced it. It has to do with remembering which drivers were loaded the last time the OS ran and loading those first on reboot. Saves time on checking the whole driver catalog.

[AshamedCaptain]

I remember at the time some propaganda about XP doing "concurrent initialization" for some drivers. My impression is they just fine-tuned some of the IO delay loops (or equivalent). Most of the Win2k boottime is spent with no CPU or disk usage. XP is way more efficient at that.