tools, options, plotting tab. for 2k2 and 2k4 it is in the lower left hand corner. Select Hide system plotters.
for 2k5 and maybe 2k6, plot and publish tab, right side about 2/3rd down
there is Hide system printers.
probably would be a variable somwhere that it could be set....
need to look into that as that would be helpful...
Pieter