server bandwidth limited

i had a server running iss on win 2000 advanced server, i re-installed to
just xp pro and ran apache as the web server i notice a significant decrease
in speed since then, anyone know what this could be and how to fix it, the
old serv could serv up files at 150 and 200 kbs the new setup maxes out a 45
or 50 on a good day, what could cause this?

itsrainin