SCUA Security 2000 - Version 7.12 Windows NT/XP/2000 are being used in a lot of companies nowadays. Although these operating systems have several security mechanisms, it is not difficult to reveal considerable security holes and the inefficiency of several mechanisms. Above all, the restriction of user's rights for the access to objects and sensitive data is inadequate and for this reason, the badly use of information for people without authorization is easily possible without additional measures of safety.After being authenticated with success, the user can also be authenticated automatically in heterogeneous networks through "Single Sign On". Trivial or unwanted passwords can be forbidden and the number of tentative of disable logon can be restricted.It is possible to prohibit the execution, creation, reading, writing, deletion and renaming of file types (selected by extensions) in general or for selected drives. Through the cryptography, the storage and the transfer of sensitive data in network environment can be protected against people's attacks without authorization.