做了一个登录框 提示：不可识别的数据库格式。求解

我做了张数据库的表，不知错在那里，请指教，我做了一个带登录框，有用户名和密码要用到这个数据库，总是提示：“不可识别的数据库格式”。请教高手我数据库格式错在那儿？  

Private Sub Command1_Click()
Dim sql As String
Dim conn As New ADODB.Connection
Dim rs_login As New ADODB.Recordset
If Trim(Text1.Text) = "" Then               '检测用户名正确与否
    MsgBox "用户名不能为空，请重新输入！", vbOKOnly + vbExclamation, "错误"
    Text1.SetFocus
Else
    sql = "select * from Test where test_info  = '" & Text1.Text & "'"
    rs_login.Open sql, conn, adOpenKeyset, adLockPessimistic
    If rs_login.EOF = True Then
        MsgBox "用户名不存在，请重新输入！", vbOKOnly + vbExclamation, "错误"
        Text1 = ""
        Text1.SetFocus
    Else                                        '检测密码正确与否
        If Trim(rs_login.Fields(1)) = Trim(Text2) Then
            rs_login.Close
            Unload Me
            Form2.Show
        Else
            MsgBox "密码错误，请重新输入！", vbOKOnly + vbExclamation, "错误"
            Text2.SetFocus
        End If
    End If
End If
End Sub


Private Sub Command2_Click()
    MsgBox "您已成功退出！", vbOKOnly + vbExclamation, "提示"
    Unload Me
End Sub


Private Sub Form_Load()         '此段代码的主要作用是当窗体打开时就连接数据库
Dim conn As New ADODB.Connection
Dim connectionstring As String
connectionstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & "E:\Test.mdb;Persist Security Info=False"          '将Data Source 处的路径改为你本机数据库所在路径即可
conn.Open connectionstring
End Sub