Incredible comment of an sysadmin active-duty sailor of the US Navy Marine Corps found on wired
Ships run the Common PC Operating System Environment (COMPOSE). It's essentially a Windows server with a huge and insanely convoluted proprietary set of applications that are all somehow dependent on one another. Not a day goes by where there isn't something that isn't working correctly on the network, and when you dedicate time and effort to troubleshoot the problem and then report your findings back to the SME's at SPAWAR or Juno, you're told to reinstall the entire server! It's like someone at Juno decided that since they can't control the network on the ship, they'll just make it such a complicated piece of crap that we'll have no choice but to turn to them and ask why we can?t do something as simple as change a password using their proprietary tools.
IT people on these ships only seem to have user level accounts and have to call helpdesk themselves which is a government service and only available during working hours. Increbible. That's how these huge battle ships are run? If some nation thinks about invading the U.S., it should maybe consider hiring some virus programmers instead of soldiers :)