First question would be has the cartridge got ink in. If one of the colours has run out then u have to change the cartridge even if there are other colours left. It depends on the make of printer, if u go into printers and then double click the printer to open the status window, click on printer and then to printer preferences usually in there on one of the tabs u might find a toolbox, these usually align cartridges, clean them etc. If u're using vista it'll be similar just can't remember off the top of my head.
