Data source name not found and no default driver specified

Hvorfor får jeg denne fejl:

Microsoft OLE DB Provider for ODBC Drivers error '80004005'
[Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

Jeg får fejlen i denne:

Function dbOpen()
    Connection_string = "Driver={mysql};Server=IP;Database=DB;UID=Navn;PWD=Password;"
    Set Conn = Server.CreateObject("ADODB.Connection")
    Set RS = Server.CreateObject("ADODB.Recordset")
    Conn.Open Connection_string
End Function