During the installation of RC0, setup reported that computer is not connected to Internet.
1. This is incorrect. Moreover, there's NO way to make such decision. A failure to reach some URL is not an indication that there's no Internet access. You should choose the correct wording and report just a failure to reach specific URL *and* report exact error (Winsock error code or fully Proxy response - whatever you got).
2. In this particular case, the detection itself was incorrect. The URL is accessed correctly, under the same account on the same machine.