failed to access access db

Imports System.Data.OleDb
Public Class frm_patientrecords
    'making the database connection
    Dim con As New OleDbConnection
    Private Sub DataGridView1_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
        con.ConnectionString = "Provider=microsoft.jet.oledb.4.0; data source = C:\trail.accdb"
        con.Open()
        datagridShow()
    End Sub
    'call the grid property and object
    Private Sub datagridShow()
        Dim ds As New DataSet
        Dim dt As New DataTable
        'parse the data set into the table
        ds.Tables.Add(dt)
        Dim da As New OleDbDataAdapter
        da = New OleDbDataAdapter("select * from patients", con)
        da.Fill(dt)
        DataGridView1.DataSource = dt.DefaultView
        con.Close()
    End Sub
End Class