For Qt Creator 2.4.0
If you find a valid Qt installation under Tools > Options > Build & Run > Qt Versions. If you have no valid Qt installations here you might need to rebuild from source or download the procompiled libraries from qt.nokia.com and add them manually.
When you have a valid Qt installation showing up there which one to build against by opening the Projects tab on the left sidebar. Under Build Settings > General you can select the Qt version AND which toolchain to use for various builds.
To compile Qt framework yourself with Visual C++ compiler (MSVC) from VS2013 you can use this tutorial on Building Qt 5 from Git.
Here is my short version of this tutorial above (for Windows 7 (amd64) and OpenGL):
1. Install Visual Studio 2013 (may be VS2013 Express edition).
2. Install Git, Python, Ruby, and Perl (Yes, you will need all these tools).
There is an option in each instalation wizard to add the tool to the PATH variable. Check this option or add it yourself.
3. Go to: Windows Start Menu -> All Programs -> Visual Studio 2013 -> Visual Studio Tools
Run: VS2013 x64 Native Tools Command Prompt
This is the same as run a cmd and then execute:
> C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat amd64
4. Go to a folder you want, clone Qt repository, and initialize it.
> git clone git://gitorious.org/qt/qt5.git qt5
> cd qt5
> git checkout stable
> perl init-repository
If you don`t need WebKit you may run:
> perl init-repository --no-webkit
5. Configure and compile.
> configure -developer-build -opensource -confirm-license -nomake examples -nomake tests -opengl desktop
> nmake
Done.
Best Answer
You have to add it manually then. In the Build & Run settings, compiler tab, click add, custom -> C++, then fill the compiler line with the compiler's path.
But you have to fill correctly the ABI line, and if it doesn't fit any Qt build you already made, then you will have to build Qt from source again from a msvc command prompt.