Check for active internet connection

Obviously, your problem has many levels. You should start by defining "connected to the internet", and go on with developing fallback strategies that include not writing invalid files on failure.

As for the "am I connected" question, you can try tapping into the Win32 API:

Private Declare Function InternetGetConnectedState Lib "wininet.dll" _
(ByRef dwflags As Long, ByVal dwReserved As Long ) As Long

Public Function GetInternetConnectedState() As Boolean
  GetInternetConnectedState = InternetGetConnectedState(0&,0&)
End Function

Though depending on your network setup (proxy/NAT/firewall restrictions etc.), Windows might have a different opinion about this than you.

Trying to GET the pages you are interested in, checking on the return status in the HTTP headers (gateway timeout, 404, whatever you expect to happen when it "doen't work) might also be a way to go.

You could use MSXML library & use XMLHttpRequest class to check for things

e.g.

On Error Resume Next
Dim request As MSXML2.XMLHTTP60
request.Open "http://www.google.com"
request.Send
Msgbox request.Status

The status will give you HTTP Status code of what happened to the request. You might have to do some more checks, depending on your scenario.

Hope that helps.

Use the following code to check for internet connection first anable XML v6.0 in your references

Function checkInternetConnection() As Integer
'code to check for internet connection
'by Daniel Isoje
On Error Resume Next
 checkInternetConnection = False
 Dim objSvrHTTP As ServerXMLHTTP
 Dim varProjectID, varCatID, strT As String
 Set objSvrHTTP = New ServerXMLHTTP
 objSvrHTTP.Open "GET", "http://www.google.com"
 objSvrHTTP.setRequestHeader "Accept", "application/xml"
 objSvrHTTP.setRequestHeader "Content-Type", "application/xml"
 objSvrHTTP.Send strT
 If err = 0 Then
 checkInternetConnection = True
 Else
  MsgBox "Internet connection not estableshed: " & err.Description & "", 64, "Additt !"
 End If
End Function