HP DeskJet 810C won't print with XP OS

I've got a friend who can't print anything from Word Processors. The test page prints fine and pages from the internet print fine. I've tried re-installing the printer and the printer drivers and the word processors but to no avail. I checked the HP site and the diagnostic programs there say the printer is cabled correctly and communicating with the computer and has the right driver. When I tried to get an updated driver from HP the site said the driver on the MS XP install disk was the best one to use. The HP 810C is set as the default printer. When a file is sent from Word, Wordpad or Notebood the printer starts, the head moves back and forth and a blank sheet is output. Anyone got a clue?