parallel port problem for printers

I had to install a 25 pin port for my printers to my Dell 3100 2 years ago and for some reason it stopped working...I thought it was my data switch but I bought a new one so it's not that.  I don't think my cables are bad either.  I can't find any instructions on whether I should delete the port and re-add it but it's like my computer is not communicating with my printers at all.  It just sits in the print que on windows XP and turns into an unspecified error.  Any help would be appreciated.

Thanks

Rhonda