Your firewall is your first line of defense against unauthorized access to your data. The rest depends on the security provided by the configuration of your operating system.
In a domain environment the right use of user ids and strong passwords provides the first strategy to keep your data secure, also the location and security of your data on folders with the right access to an individual or groups provide an extra layer of security. Regardless of the security you put in place, you must make sure that your most important data is backup up daily and constantly check to make sure you can recover and continue your everyday business.
