First of all, remove everything you already have (Qt SDK, eclipse, MinGW, any edits to environment Variable(s), etc. )

Now follow these steps:
  1. Download and unpack Eclipse IDE for C/C++ Developers to C:\eclipse
  2. Download and run the Automated MinGW Installer, and don't forget to select (in addition to MinGW Tools), MinGW Make and the G++ compiler and install in the default path
  3. Download and install the GDB, keeping all options default
  4. Download and install MSYS again keeping all options default, and when the installation ends, you'll see a prompt (in a command line window) then choose yes twice then enter this string as is: c:/mingw
  5. Prepend (Not Append) C:\msys\1.0\bin;C:\mingw\bin; to the PATH Environment Variable
  6. Download and install Qt SDK also in the default directory.
  7. Download and install Qt Eclipse Integration for C++, all default
  8. Append ;C:\Qt\2009.01\qt\bin to the PATH Environment Variable
    Add C:\MinGW\lib;C:\Qt\2009.01\qt\lib to the Lib Environment Variable (if no Lib, please create one)
    Add C:\MinGW\include;C:\Qt\2009.01\qt\include to the Include Environment Variable (if no Include, please create one)
  9. Open eclipse and goto: "Preferences -> Qt -> Add", then give these values:
    • Version Name: 4.5.0
    • Bin Path: C:\Qt\2009.01\qt\bin
    • Include Path: C:\Qt\2009.01\qt\include
  10. Reboot your computer
  11. Click the bug icon and select "Debug Configurations", add a new configuration in C/C++ Local Application, notice that C/C++ Application should be "debug/*.exe", not "release/*.exe"! Choose the Debugger tab and set Debugger to gdb/mi. And then choose apply.


And, you're done ( finally )
HTH