vb.net, ms access link could not be established

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VB

MS-Access

Public Class Form1
    'Dim dbProvider As String = "Provider=Microsoft.ace.oledb.12.0;"
    'Dim dbSource As String = "Data Source=~\bin\Debug\EC_Database_2.accdb"
    'Dim constr As String = dbProvider & dbSource
    Dim conn As OleDbConnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & System.Environment.CurrentDirectory & "\EC_Database.mdb")
    Dim mstr As String = ""


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try

        
            conn.Open()
            mstr = "Select person_ref from QN_Person_Mast order by person_ref asc"
            Dim sda1 As OleDbDataAdapter = New OleDbDataAdapter(mstr, conn)
            Dim dt1 As DataTable = New DataTable()
            sda1.Fill(dt1)
            If dt1.Rows.Count > 0 Then
                ComboBox1.Items.Clear()
                For i As Integer = 0 To dt1.Rows.Count - 1
                    ComboBox1.Items.Add(dt1.Rows(i)("person_ref"))
                Next
            End If
            conn.Close()

        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub
End Class

I have kept the access file in bin\debug\....but the error is:

The 'Microsoft.Jet.OLEDB.4.0' provider is not registered on the local machine.
please help me....

[edit]Code block added[/edit]