Run time error '-2147467259(80004005)': automation error unspecified error

Hi Im new to VB

I trying to connect to oracle 10g data base using excel 2003 vb 6.5
Below is the code.. when i try to run.. iam getting the above error [Run time error '-2147467259(80004005)': automation error unspecified error]
Don't know to fix it. Anyone suggest solution


Sub ConnectDatabase_Click()

Dim con As ADODB.Connection
Dim rs As ADODB.Recordset
Dim query As String
Set con = New ADODB.Connection
Set rs = New ADODB.Recordset

strCon = "Driver={Microsoft ODBC for Oracle}; " & _
"CONNECTSTRING=(DESCRIPTION=" & _
"(ADDRESS=(PROTOCOL=TCP)" & _
"(HOST=Teddy)(PORT=1521))" & _
"(CONNECT_DATA=(SID=25))); uid=33; pwd=admin;"


con.Open (strCon)


End Sub