For Windows XP computers that are not part of a Domain (they are stand-alone, or part of a workgroup), the default is to have the Security tab hidden.
To reveal the Security tab follow three simple steps:
Open Windows Explorer, and choose Folder Options from the Tools menu.
On the View tab, scroll to the bottom of the Advanced Settings and clear (click) the check box next to “Use Simple File Sharing.”
Click OK to apply the change, and you should now have a Security tab when viewing the properties of a file on an NTFS volume.