HP Jetdirect 250M User Manual page 42

Essentially, you are finished with the installation process when you have a
network printer installed on your computer and you can print to it. That's usually
when the test page prints successfully.
If you have two CDs -- a printer CD and the HP Jetdirect CD -- and you have just
run the installer from the printer CD, it's common to wonder whether you should
be running the installer on the Jetdirect CD as well. ("After all, that second CD
must be there for a reason. Maybe I should run that installer, too, just to be sure. .
. .") You don't need to do that. Once your network printer prints successfully,
you're done. (We put the installer on the Jetdirect CD for situations where you
can't find your printer CD, or where the printer CD's installer doesn't deal with
network printers. If your printer CD does handle network printers, just run that
installer and stop when it's done.)