@ChrisW67
Hi, I've just managed to build qt with GCC 5.1. I do want to thank you for your help.
The command line I've used:
configure.bat -release -platform win32-g++ -opengl desktop -qt-zlib -qt-pcre -qt-libpng -qt-libjpeg -skip webkit -nomake examples -nomake tests -no-accessibility -skip activeqt

Thanks again.
Peace man.