Hi Pauline, Read the above posts, if you haven't already done so. Look at #4 and #21 in particular. Look also on the Nikon site - Support - update camera firmware ---the firmware description for the D200 ought to give you directions for use/download/installation. All of that being said I've got the notion that you may have more amiss than DBS - PM or e-mail poster #21 for help, since he's had the problem. What I'd be inclined to do though, with the camera cutting out as it is, is to go straight to an authorized Nikon service center and--hope for the best. Good luck!
Time for the update is several minutes for A, slightly longer for B update.