hp laserjet 6l printer with windows 7

I just got a dell inspiton 560 and have two printers which I want to attach.  I have been successful with the hp deskjet 812c, using the virtual usb port 001 in windows 7.  But, I just cannot get the computer to recognize the hp laserjet 6l.  I have tried everything I could possibly think of.  Someone told me that I should just use the same virtual usb port 001 (since that is the only usb one there), and the computer should just recognize and install the printer.  I downloaded updated drivers for the printer too.  I had to use a parallel to usb adapter in order to attach the printer.  Is it ever possible that there could be something wrong with this cable?  I can't think of anything else, and neither can anyone else that I have talked to.  Someone please help!! Thank you