I am using the dell laptop in which I am running windows vista. I am also using HP8500 printer. I have replaced my printer cartridge before some days because my old cartridge gets dry up. After installing the new cartridges I am able to print the documents but I am not able to print black color in my printer. I donít know what went wrong but this problem is really irritating me. Please tell me how to find where the problem is? Please reply me as soon as possible.