When opening maintenance kit instruction sheets using internet explorer you will need to save the pdf first before you can open it. If you are using Firefox you will have the option to either open it or save it. Instructions Sheets for HP Laserjet 4_4+_5 Instructions Sheets for HP Laserjet 42XX Instructions Sheets for HP Laserjet 5000/5100 Instructions Sheets for HP Laserjet 8100_8150 Instruction Sheets for HP Laserjet 9000 Instruction Sheets for HP Laserjet 4000_4050_4100 Instruction Sheets for HP Laserjet 2100_2200_2300 Instruction Sheets for HP Laserjet 2400