The most common cause of this is the printers drivers for the parallel port have been installed by mistake.
When you insert the Driver CD (from Epson, HP etc) the autorun utility may automatically try to install the software for the parallel Port.
If you want to connect the Printer by USB it is IMPORTANT NOT TO INSTALL THE SOFTWARE IN THIS WAY.
If you have installed any printer software then please remove it before proceeding.
To install a USB printer (this has worked for all printers that we come across so far)
1. Power Up the printer without the USB cable plugged in (but plugged into the PC).
2. Connect the USB cable into the printer and windows should pick up the device.
3. When asked for drivers - browse the printer driver CD for a directory called Win9xUSB (or something similar) .
4. When the Printer USB drivers have been installed it will automatically pull in any printing software required.