Look at InternetAttemptConnect. I've found it's the most reliable.

>Hi,
>
>in my application I want to check if there is an open Internet connection and if there is not - force the connect with the default dial-up connection.
>
>I tried this:
>DECLARE INTEGER InternetGetConnectedState IN Wininet.dll STRING@, INTEGER
>res = PADR('', 4, CHR(0))
>? InternetGetConnectedState(@res,0)
>
>The return value is 1(which is guess TRUE) so there is an open Internet conection, but then I disconnected and running the same function I got the same result???!!! In the res dword I got back 18(which I don't know what it is - the spec is talking about values 1,2,4,8)
>
>After this confusing result I tried:
>DECLARE INTEGER InternetAutodial IN Wininet.dll INTEGER,INTEGER
>? InternetAutodial(1,0)
>** 1 stands for: "Forces an online Internet connection"
>
>with no Internet connections this functions returns 0
>With Internet connection returns 1.
>But I expected to pop up the default dial-up connection.
>
>What else can I use?
>
>I tried this function:
>DECLARE INTEGER RasEnumEntries ;
> IN rasapi32.dll ;
> STRING reserved,;
> STRING phonebook,;
> STRING @rasentry,;
> INTEGER @lnSize,;
> INTEGER @lnEntries
>
>lcBuffer = PADL('', 20*(4+257), CHR(0))
>lnlen = len(lcbuffer)
>ln2=0
>? RasEnumEntries(chr(0), "",@lcBuffer,@lnlen,@ln2)
>
>I got back an error message saying :
> ERROR_BUFFER_INVALID
>
>Any suggestions?
>
>Thanks,
>Vali