Question : Problem: HP Color LaserJet 4550 - Which parallel-USB adapter?

I have a user with an HP Color LaserJet 4550 Printer. The user ordered a "GUC1284B USB to IEEE-1284 Bi-directional Printer Cable from IOGEAR®" from Dell, but upon receiving the part she found that the adapter did not fit the printer port or printer cable. What part do I need to connect this printer via USB to a PC running XP or Vista?

Answer : Problem: HP Color LaserJet 4550 - Which parallel-USB adapter?

You'll need a USB to Mini-Centronics (IEEE 1284-C or IEEE 1284C) cable but even then USB to Centronics is not 100% reliable with bi-directional support for printing. You might be better off connecting it via ethernet to a JetDirect box.

Cable recommended by HP forums here:
http://sewelldirect.com/USB-to-Mini-Centronics-Combo-Cable-Set.asp