One year and it seems to work. However that mucks up emails and more.
Read http://www.theinquirer.net/?article=9250 for another method but you are on your own.
I have HP business inkjet 2250 which uses individual ink cartridge(cyan magenta yellow and black) for printing. Each cartridge has expiration date electronically stamped so the printer became disabled once it reaches expiration date. Does anyone know how to bypass this? I called HP and they said they can teach us. But they have to charge me which cost more than the cost of these ink cartridges. HELP!