My desktop tech brought me a 386 that had a failed hard drive due to a building collapse (a longer story). It was part of a 3 computer "network" that housed a database of "drug buy" money for the local police department. We replaced the harddrive and put DOS and the database back on it (via floppy backup no less). To the best of my knowledge, it is still in service today. That is how you keep the hackers out!