[edit] Get the Qt4 source code

Open Source developers: check out qt-copy from http://websvn.kde.org/trunk/qt-copy/ with your favorite svn client.

[edit] Apply the KDE patches

Patch the source code with KDE's own patches first: run patches\apply_patches.bat.

[edit] Configure Qt

You will need openssl support - so make sure it's enabled! Also make sure that configure.exe find openssl headers and libs:

qconfigure {PLATFORM} -openssl -I "<path to openssl headers>" \
-L "<path to openssl libs>" -qdbus -I "<path to windbus headers>" \
-L "<path to windbus libs>"

{PLATFORM} can be msvc for MSVC 6.0, msvc.net for MSVC .NET (2002 (7.0) or 2003 (7.1)), msvc2005 for MSVC 2005 (8.0) or msvc2008 for MSVC .NET 9.0 (2008). This is needed to simplify path names in the future if you did not use the commercial configure.exe GUI installer:

set QTDIR={your qt installation directory}

Note: this (QTDIR) and the subsequent environment variables described below on this page could be set globally in the "System" applet, Advanced->Environment Variables. Optionally, if you want to have multiple configurations (e.g. Qt3 and Qt4) on the same machine and account, you can enter appropriate set commands into a single .bat file, e.g. environment.bat which you can then execute once in a new cmd shell.

See also alternative instructions at QtCentre.net.