Hi,
I assume you have Windows XP.
I also assume you have loaded the driver for the USB to Parallel converter.
Try going to :
Setting, Printers and Faxes, Your PC 600, then go to Properties NOT Preferences.
You will see a "port" tab which should have quite a few choices.
BE CAREFUL !!!!!!
You might have to click a virtual port since the USB is imulating a Parallel port.
I'm note quite sure without being at your computer, but I think if there is a chance to make it work, this might be the right direction.
Also, check your USB converter manual, they mught assign, for example, LPT5, as your printer connection for the USB convereter.
I hope this helps.
Chris