Public Function DoFullAccessFileFolder(ByVal FileFolderPath As String) As Integer
    DoFullAccessFileFolder = AddAceToObjectsSecurityDescriptor(FileFolderPath, _
     SE_OBJECT_TYPE.SE_FILE_OBJECT, _
     ConstructUniversalAndNTWellKnownSids("Users"), _
     GENERIC_ALL, _
     ACCESS_MODE.GRANT_ACCESS, _
     CONTAINER_INHERIT_ACE Or OBJECT_INHERIT_ACE)
    If DoFullAccessFileFolder <> ERROR_SUCCESS Then
      AddLog("  Calling AddAceToObjectsSecurityDescriptor... Failed. Error code: " & RaiseAPIErrorByNumber(DoFullAccessFileFolder))
    Else
      AddLog("  Calling AddAceToObjectsSecurityDescriptor... Done.")
    End If
  End Function


  Public Function AddAceToObjectsSecurityDescriptor(pszObjName As String, _
   ObjectType As SE_OBJECT_TYPE, pszTrustee As String, _
   dwAccessRights As Integer, AccessMode As ACCESS_MODE, dwInheritance As Integer) As Integer
    'DWORD AddAceToObjectsSecurityDescriptor (
    '    LPTSTR pszObjName,          ' name of object
    '    SE_OBJECT_TYPE ObjectType,  ' type of object
    '    LPTSTR pszTrustee,          ' trustee for new ACE
    '    TRUSTEE_FORM TrusteeForm,   ' format of trustee structure -<не надо
    '    DWORD dwAccessRights,       ' access mask for new ACE
    '    ACCESS_MODE AccessMode,     ' type of ACE
    '    DWORD dwInheritance         ' inheritance flags for new ACE
    ')

    Dim dwRes As Integer
    Dim pOldDACL As IntPtr, pNewDACL As IntPtr
    Dim pSD As IntPtr
    Dim ea As New EXPLICIT_ACCESS

    If (pszObjName = "") Then
      AddAceToObjectsSecurityDescriptor = ERROR_INVALID_PARAMETER
      Exit Function
    End If

    'Get a pointer to the existing DACL.
    dwRes = GetNamedSecurityInfo(pszObjName, ObjectType, _
     DACL_SECURITY_INFORMATION, _
     IntPtr.Zero, IntPtr.Zero, pOldDACL, IntPtr.Zero, pSD)
    If dwRes <> ERROR_SUCCESS Then
      AddLog("    Calling GetNamedSecurityInfo... Failed. Error code: " & RaiseAPIErrorByNumber(dwRes))
      'MsgBox "GetNamedSecurityInfo Error " & CStr(dwRes)
      GoTo Cleanup
    Else
      AddLog("    Calling GetNamedSecurityInfo... Done.")
    End If

    'Initialize an EXPLICIT_ACCESS structure for the new ACE.
    'BuildExplicitAccessWithName(ea, pszTrustee, dwAccessRights, AccessMode, dwInheritance)
    '-по каким-то причинам эта ф-ция вызывает crash
    'поэтому инициализируем ea-структуру вручную согласно описанию ф-ции
    'pTrusteeName-A pointer to a null-terminated string that contains the name of the trustee for the ptstrName member of the TRUSTEE structure.
    'The BuildExplicitAccessWithName function sets the other members of the TRUSTEE structure as follows.
    'pMultipleTrustee    NULL
    'MultipleTrusteeOperation    NO_MULTIPLE_TRUSTEE
    'TrusteeForm    TRUSTEE_IS_NAME
    'TrusteeType    TRUSTEE_IS_UNKNOWN
    With ea
      .grfAccessPermissions = dwAccessRights
      .grfAccessMode = AccessMode
      .grfInheritance = dwInheritance
      .pTrustee.pMultipleTrustee = IntPtr.Zero
      .pTrustee.MultipleTrusteeOperation = MULTIPLE_TRUSTEE_OPERATION.NO_MULTIPLE_TRUSTEE
      ea.pTrustee.TrusteeForm = TRUSTEE_FORM.TRUSTEE_IS_NAME
      ea.pTrustee.TrusteeType = TRUSTEE_TYPE.TRUSTEE_IS_UNKNOWN
      ea.pTrustee.ptstrName = pszTrustee
    End With

    ' Create a new ACL that merges the new ACE into the existing DACL.
    dwRes = SetEntriesInAcl(1, ea, pOldDACL, pNewDACL)
    If dwRes <> ERROR_SUCCESS Then
      AddLog("    Calling SetEntriesInAcl... Failed. Error code: " & RaiseAPIErrorByNumber(dwRes))
      'MsgBox "SetEntriesInAcl Error " & CStr(dwRes)
      GoTo Cleanup
    Else
      AddLog("    Calling SetEntriesInAcl... Done.")
    End If

    'Attach the new ACL as the object's DACL.
    dwRes = SetNamedSecurityInfo(pszObjName, ObjectType, _
     DACL_SECURITY_INFORMATION, _
     IntPtr.Zero, IntPtr.Zero, pNewDACL, IntPtr.Zero)
    If dwRes <> ERROR_SUCCESS Then
      AddLog("    Calling SetNamedSecurityInfo... Failed. Error code: " & RaiseAPIErrorByNumber(dwRes))
      'MsgBox "SetNamedSecurityInfo Error " & CStr(dwRes)
      GoTo Cleanup
    Else
      AddLog("    Calling SetNamedSecurityInfo... Done.")
    End If

Cleanup:
    If pSD <> IntPtr.Zero Then LocalFree(pSD)
    If pNewDACL <> IntPtr.Zero Then LocalFree(pNewDACL)

    AddAceToObjectsSecurityDescriptor = dwRes
  End Function