If you have built a 'release' version of your program, copy it and the following DLL's from qt\bin to a directory:
If you are running a 'debug' build, you will need the debug versions of the Qt DLLs. They have the same name but with a 'd' at the end of the name.
- QtGui4.dll and
- (if you are compiling with gcc and minGW).
There may be other Qt DLLs you will have to copy depending on Qt modules you are using in your program.