scanner & printer installation

Hi,
I installed a new scanner,visioneer 8100 onetouch, I have a HP 812 C printer, connected them as thy instructed, (I think)
but~ when I turn the scanner on, the printer says printer is not connected to computer.
I turn the scanner off, and I can print anything I want to. what did I do wrong?
I am running WI 98 had no problems with my old scanner, so ,I figure ,I did something wrong.
could someone tell me what?
thanks
Tanja