devastating events the nation has ever encountered. >> the brains of most computers, the chips that do the thinking have tiny built-in clocks. many registered the year with only the last two digits assuming the first two are always 19. >> the problem was not the computer would think that it's 1900. the problem was it wouldn't know what to do. it would just break down and go err, can't process this. >> it could trigger widespread computer failures blackouts and breakdowns of everything from home appliances to the global financial system. >> if we left things as they are right now, the military would effectively shut down. >> the pentagon will spend at least $4 billion to defuse the millennium bomb and pentagon officials are confident they'll do it. but critics claim they started too late, and those thousands of fixes won't be done in time. >> many states have not updated their computers that run programs such as medicaid and