Qt Application Icon doesn't work

Qt Application Icon doesn't work

I created a small .ico for my program. Now I want Qt to set it as the
applications icon.
I found this documentation but it doesn't seem to work :
http://qt-project.org/doc/qt-4.8/appicon.html
I did exactly what they want me to do.
Create an myapp.rc file and write IDI_ICON102 ICON DISCARDABLE
"Movie-World.ico" into it. -> Did that.
Write RC_FILE += myapp.rc into your .pro file.
-> Did that.
When I compile and run, it doesn't work. I deleted the realese folder but
still no changes. I restarted Qt but still no changes.
I even added win32: before RC_FILE += myapp.rc but it did not work...
I don't understand why. My files are all in the same directory.