Cygwin Setup Hangs at 00bash.sh

I tried to install the latest cygwin from cygwin.com. The setup window hangs forever at 98% while running 00bash.sh. When I click the cancel button, the popup window says something like the cygwin has been installed successfully. But I can't even start a bash terminal, which means the installation has not completed successfully.

I then googled with "cygwin install hang 00bash.sh", and the best result seems to be this link:

It suggests running each step in 00bash.sh manually, which I did and got the same result.

I've been using cygwin for years and this is the first time I've seen this error. The next morning, I came to realize the culprit could be Norton Internet Security 2006. After I disable it, everything is working all right.

The bash program calls some network services (uname.exe, find.exe, hostname.exe), which are by default blocked by Norton Internet Security 2006 without giving user the options.