We have a HP LJ2100tn. It is old and shared off of a XP computer, and we have an OKI C5150. I only buy HP for it, I buy on Ebay. As far as I know, they are all genuine cartridges. On the Oki, it is our color printer, and we only turn it on when we need color, and have never changed a cartridge in it yet. I would like to sell both printers and buy a Xerox Phaser series.