Try
            Dim Ricerca
            Ricerca = txtRicerca.Text

            Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=c:\Temp\data.mdb;")
            Dim cmd As OleDbCommand = New OleDbCommand("Select * FROM tbNominativi where nominativo'" & Ricerca & "'", con)
            con.Open()
            Dim myDA As OleDbDataAdapter = New OleDbDataAdapter(cmd)
            Dim myDataSet As DataSet = New DataSet()
            myDA.Fill(myDataSet, tbNominativi)
            DataGridView1.DataSource = myDataSet.Tables("tbNominativi").DefaultView

            con.Close()
            con = Nothing
        Catch ex As System.Data.OleDb.OleDbException
            MsgBox(ex.Message)
        End Try