Qt for Windows Requirements
If you are using a binary version of Qt with Visual Studio 2005, you must first install the Visual Studio Service Pack 1 available here to avoid runtime conflicts. Additionally, you must use the Check for Updates feature in the Help menu of the Visual Studio 2005 IDE to apply at least the following security updates: KB937061, KB971023, KB971090, KB973673.
If you are using a source edition of Qt, you must first install Perl so that the syncqt script invoked by configure can be executed. You can download this here.
To build Qt with Phonon on Windows, you require:
See also Known Issues.