Wow. Will try the easy ones first, but some additional info: it just suddenly refused to start up normally today after behaving fine the day before, and being shut down properly. All relevent troubleshooters seem to be assuming that something new has been improperly added but I haven't loaded anything in months (AOL sometimes updates itself but not yesterday). Have rebooted, cold and hard. Have done stuff calculated to get me into You Didn't Shut Down Right You Naughty User, but it doesn't. Ran Scandisk anyway, and it kept quitting because programs were writing when nothing was running. When it finally ran it found nothing wrong. I do defrag regularly but not yesterday.