Possibly because you deleted fonts that *weren't* as "excess" as you
thought
and they were system fonts. Or else possibly you have one of the many
security programs installed that prevents changes to the registry; eg.,
Norton, McAfee, Ad-aware Pro, Spybot Search & Destroy w/Immunization, etc.
BTW, having lots of fonts installed doesn't slow down your system in XP
the
way it did in Win98.