Granting, Revoking, and Denying Permissions
The ServerPermission object is used to assign a set of permissions or an individual server permission to the ServerPermissionSet object. For server level permissions, the grantee refers to a logon. Logons authenticated by Windows are listed as Windows user names. When this code sample runs, it revokes the permission from the grantee and verifies it has been removed with the EnumServerPermissions method.