WinHTTP Default Network Adapter

[Jimmie Tyrrell]

Note: Please inform me if you know a better place to post this :)

--

I wrote some software the uses WinHTTP to perform some HTTP
transactions. On most computers, it works great. For some users,
however, the code fails to connect to the web.

One user had two network adapters - one that was online, one that was
offline (the red, x system tray icon). I told the user to completely
disable the offline adapter, and magically the software began to work
for him.

So I'm assuming that Windows has a way of defining a primary adapter,
and for some reason, when that adapter is offline, it fails to choose
another adapter.

Ideally, I'd like the software to determine an available network
adapter automatically. Another option is that the user can select an
adapter for WinHTTP to use. Are there any common practices to achieve
either?

Thank you very much in advance,