When my old computer with XP finally failed last August, I got a new Dell with Win 7 on it. Guess what - no serial port for my trusty 1996 HP LaserJet 6P printer. I was told to buy a new one and forget about it. I refused and researched the problem. I bought a cable from Amazon with detailed instructions on how to configure and BINGO - my trusty printer is now back in operation.
I take care of printers at work and the 6p is the Honda Civic of printers. I still have a couple running.