When I want to use my scanner, I unplug my printer and plug in my scanner.

That is a major inconvenience. So I bought a USB/Parallel port adaptor to plug into the front USB port. It self installed. Noted as working properly, but plugging it in with either the scanner or printer does not work.

Although, the scanner does work through the printer port, when I try to run it thru the USB adaptor, one of the options states to set the BIOS to EPP mode. Is that an anomoly of the USB and is that all or nothing which might not let the printer port function if I did change it?

EPP= Enhanced Parallel Port. I haven't used a parallel printer in over 10 years. Try setting the bios to EPP. You can change it back if you need to. What version of Windows are you running?

USB/Parallel

I meant to edit my post. I checked the set-up. It's already set to EPP, so that wasn't the problem,

I'm running XP Home.

I'm not sure if this post and attachment has any relevance: http://www.techspot.com/vb/topic112380.html#post664305
But does sound as though you need an additional driver