well i'm not a VPC professional but just from reading your post it seems like there is some confusion between the two operating systems.
for instance you write:
It asked me to check the status of the device (while in Windows 98 in Virtual PC mode) by selecting, "Start", "Settings', "Control Panel", dbl click on the System Icon, click on the Device Manager tab and then click on the + sign next to Universal Serial Bus Controllers. There should be at least two devices listed: USB Universal Host Controller and USB Root Hub.
simple enough but than you wrote:
I've done a search on the Apple Web-site but don't come up with any matches for Universal Serial Bus Controller, USB Universal Host Controller or USB Root Hub.
if these drivers are missing from the Windows installation why would Apple be able to help?
Instructions from the device notwithstanding its a Windows problem. Are you absolutely sure that you are running Windows 98? since Windows 95 dosen't support any USB stuff. (from the sounds of it there is no USB drivers in the windows operating system.)
if the virtual PC installation is older it may only have Win95. if it is windows 98 you may need to reinstall the missing USB components from the win 98 CD. They may have been damaged or not installed because some fluke in the emulated environment made it "think" there was no USB to install components for.
So this is my advice:
A. be sure you are running Win 98 not Win 95.
B. if its win 98. try to do a reinstall of the windows software. (warning: you will also need to reinstall all windows games and other software)
C. i would call the Virtual PC people they may know of an issue with windows not recognizeing the USB ports and therefore skipping the USB drivers.
D. Apple can't help here.
Running virtual PC on a mac is complex, you are entering the geeky world of emulated computing environments. in which the trouble shooting guide is often not much help.
(ex. contacting the manufacturer)
try this link:
http://www.macwindows.com/
go to the right sidebar I saw a section for Emulators I'm sure ther is plenty of information there.
good luck
Mike