After downloaded and installed Qt SDK for Windows 4.6.2, the first time, I tried the famous example, fancybrowser, it is no problem to open http://www.google.com/ncr, but when I clicked the Gmail link on the Google home page, I got the following error message,
QSslSocket: cannot call unresolved function SSLv3_client_method
QSslSocket: cannot call unresolved function SSL_CTX_new
QSslSocket: cannot call unresolved function SSL_library_init
QSslSocket: cannot call unresolved function ERR_get_error
QSslSocket: cannot call unresolved function ERR_error_string
After a quick search, I noticed OpenSSL is not installed, so needs an OpenSSL for Windows. I tried Win32 OpenSSL and GnuWin OpenSSL for Windows, both works.
For Win32 OpenSSL, just download Win32 OpenSSL v1.0.0 Light or Win32 OpenSSL v0.9.8n Light(both need Visual C++ 2008 Redistributables), install it(i used Universal Extractor unpack them then copy libeay32.dll and ssleay32.dll to windows system folder). For GnuWin OpenSSL for Windows, just download openssl-0.9.8h-1-bin.zip then extract libeay32.dll and libssl32.dll to windows system folder or mingw bin folder (installed with qt).
P.S.
The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library.