vb6.0中用adodc控件连接sql2005

Question

vb6.0中用adodc控件链接sql2005 设置connectionstring属性的时候，点击在服务器（本机）上选择数据库，总是出现[DBNETLIB][connectionOpen (connect()).]SQL Server 不存在或拒绝访问
为此数据库也重装过了，SQLserver服务已全部开启。。
苦苦找不到原因，急。。。。。哪位高手能指点迷津，谢了。。。。。

Answer 1

VB连接SQL数据库的模块:
Public conn As New ADODB.Connection
Public rs As New ADODB.Recordset
Public addFlag As Boolean

Public Function OpenCn() As Boolean
Dim mag As String
On Error GoTo strerrmag
Set conn = New ADODB.Connection
conn.ConnectionTimeout = 25
conn.Provider = "sqloledb"
conn.Properties("data source").Value = "127.0.0.1" ''服务器的名字
conn.Properties("initial catalog").Value = "chart" ''库名
conn.Properties("integrated security").Value = "SSPI" ''登陆类型
conn.Open
OpenCn = True
addFlag = True
Exit Function
strerrmag:
mag = "Data can''t connect"
Call MsgBox(mag, vbOKCancel, "Error:Data connect")
addFlag = False
End
End Function

Public Sub clocn()
On Error Resume Next
If conn.State <> adStateClosed Then conn.Close
Set conn = Nothing
End Sub

Public Function openrs(ByVal strsql As String) As Boolean ''连接数据库记录集
Dim mag As String
Dim rpy As Boolean
On Error GoTo strerrmag
Set rs = New ADODB.Recordset
If addFlag = False Then rpy = True
With rs
.ActiveConnection = conn
.CursorLocation = adUseClient
.CursorType = adOpenKeyset
.LockType = adLockOptimistic
.Open strsql
End With
addFlag = True
openrs = True
Exit Function
strerrmag:
mag = "data not connect"
Call MsgBox(mag, vbOKCancel, "error:connect")
openrs = False
End
End Function
Public Sub clors()
On Error Resume Next
If rs.State <> adStateClosed Then rs.Clone
Set rs = Nothing
End Sub