Public Function SetFileAttributeHidden_Net(ByVal file_path As String, _
   ByVal bHide As Boolean, Optional ByRef err_text As String = vbNullString) As Boolean
    Try
      If bHide Then
        IO.File.SetAttributes(file_path, IO.File.GetAttributes(file_path) Or IO.FileAttributes.Hidden)
      Else
        IO.File.SetAttributes(file_path, IO.File.GetAttributes(file_path) And Not IO.FileAttributes.Hidden)
      End If
      Return True
    Catch ex As Exception
      err_text = ex.ToString
      Return False
    End Try
  End Function

  Public Const FILE_ATTRIBUTE_HIDDEN As Integer = &H2

  Public Const INVALID_FILE_ATTRIBUTES As Integer = -1

  Public Declare Unicode Function GetFileAttributes Lib "kernel32" Alias "GetFileAttributesW" _
  (ByVal lpFileName As String) As Integer
  Public Declare Unicode Function SetFileAttributes Lib "kernel32" Alias "SetFileAttributesW" _
  (ByVal lpFileName As String, ByVal dwFileAttributes As Integer) As Boolean


  Public Function SetFileAttributeHidden(ByVal file_path As String, _
   ByVal bHide As Boolean, Optional ByRef err_text As String = vbNullString) As Boolean

    Dim dwAttr As Integer = GetFileAttributes(file_path)
    If dwAttr = INVALID_FILE_ATTRIBUTES Then
      err_text = "Error=" & RaiseAPIErrorByNumber(Err.LastDllError)
      Return False
    End If

    If bHide Then
      SetFileAttributeHidden = SetFileAttributes(file_path, dwAttr Or FILE_ATTRIBUTE_HIDDEN)
    Else
      SetFileAttributeHidden = SetFileAttributes(file_path, dwAttr And Not FILE_ATTRIBUTE_HIDDEN)
    End If
    If SetFileAttributeHidden = False Then
      err_text = "Error=" & RaiseAPIErrorByNumber(Err.LastDllError)
    End If
  End Function

    Catch
      err_text = "Error " & Err.Number.ToString & " (" & Err.Description & ")"

  Catch ex As Exception
      err_text = ex.ToString

SetFileAttributes(file_path, dwAttr And Not FILE_ATTRIBUTE_SYSTEM)
либо
IO.File.SetAttributes(file_path, IO.File.GetAttributes(file_path) And Not IO.FileAttributes.System)