Driver loading

just click stat-- then settings--- then printer and faxes--then on left side you will see the add printer option.there you just click NEXT-- NEXT option.and you will get to select the printer from the list.the basic printers are already loaded in the windows network.you just select the proper printer model.first select brand that is HP then select modelthat is 640.if by chance 640 is not listed you select only hp desk jet.keep your printer connected to pc this will solve the problem of drivers.