:-1: error: Qt Creator needs a compiler set up to build. Configure a compiler in the kit options.

[Titanz]

First time Qt user here. I've been trying to figure out for about an half an hour trying to fix this error. It keeps asking for compiler when I start debugging it. I have Visual Studio 2013. And I installed mingw it still looking for a compiler.

[Jeroentjehome]

Hi,
MinGw and Visual Studio are not compatible! What package of Qt did you download? There are different options for it. When you download a MSVCxxx package you are responsible of setting up your compiler yourself. Qt doesn't supply you with it because it comes with the install of MSVC.
As a first timer I would suggest that you install
Qt 5.1.1 for Windows 32-bit (MinGW 4.8, OpenGL, 666 MB)
Here the MinGw is preinstalled and configured for use together with the debugger.
Otherwise when you install VS2010 or VS2012 you could use those packages and in the manage kit section setup the compiler and debugger for it (the debugger might be dowloaded as the Microsoft development kit separate).
So, at first, getting to know Qt, use the 32 bit MinGw install and you'll be fine.
Then explore the compiler and debugger sections in the wiki pages if you are really fun of VS20xx compilers.
Greetz

Btw: Using Qt package VS2012 with the compiler of VS2013 might give very very strange linker errors or application crashes. This because all compilers may do other namemangling for the linker steps.