The NOS is responsible for securing resources on the network. If a file server exists, the NOS must ensure that the user has enough rights to view the files held on it. This prevents un-authorised access to sensitive files. This is usual in schools where each student has a user area to store work on. They should not be allowed to access other areas of the server as they do not have the rights.

When a user account is created the network manager must assign that user some rights. The user is then restricted in what they can do based on the rights they have been given.

Users are normally required to log in to show who they are. A password will be given which is checked by the NOS to see if the password is the same as the one stored. This login information will be managed by a server.

As well as access rights the network manager may wish to restrict other things. Such as giving a file and printing quota. Removing internet access or access to the hard drive. A good NOS has the ability to restrict access to most parts of the computer based on account settings.