[Microsoft][ODBC 驱动程序管理器] 未发现数据源名称并且未指定默认驱动程序……高手帮忙！！！

用vb和SQL2000做了个登录界面，代码如下

Private Sub Form_Load()
Dim Length As Long, S As String
S = String(1024, 0) '连接字符串设置
Length = GetPrivateProfileString("Connect", "ConnectString", "", S, Len(S), App.Path & "\set.ini")
constr = Left(S, Length)

Dim mysql As String
Dim myDB As Connection
Dim myForm As Recordset

Set myDB = New Connection
ConnectString = constr
myDB.Open ConnectString

mysql = "select * from userinfo"
Set myForm = New Recordset
myForm.Open mysql, myDB, adOpenDynamic, adLockOptimistic

If myForm.BOF And myForm.EOF Then
MsgBox "无用户"
Exit Sub
End If

myForm.MoveFirst
While Not myForm.EOF
User.AddItem myForm!UserID
myForm.MoveNext
DoEvents
Wend
myForm.Close
Set myForm = Nothing
myDB.Close
Set myDB = Nothing

User.ListIndex = 0
txtPassword = ""
End Sub