I've quit using legacy ports such as the serial and parallel ports. But, you can try a few things:

1. Make sure the bios and Windows have matching settings. Sometimes, Windows will read COM1 for a serial port, but not the bios. Check also your bios to make sure you have the right LPT setting. I normally left mine at 2-way traffic (bi-directional) when I was still using it.

2. Make sure the IRQ each port uses match up in both Windows and the bios.

3. Once these are done, Go to Start--->Programs--->Accessories--->System Tools and run System Information

In System Information, open Conflicts/Sharing and see which devices, if any, share an IRQ with your parallel port. Then you'll have a clearer view of what may be the problem.

4. You can also check and make sure you have a bi-directional cable connecting the pc and printer.

If at all possible, convert to usb and turn off the com/lpt ports.