Go for static build instead copying all the dlls.

1. Install QtSDK (2009.05)

2. Open your mkspecswin32-g++qmake.conf file (located in C:\Qt\2009.05\qt\mkspecs\win32-g++\qmake.conf) in an editor like notepad.

3. Find the line that starts with "QMAKE_LFLAGS = -enable-stdcall-fixup..." and ddd the phrase "-static" (without quotes) after the "=" sign and before the "-enable..." phrase, so it looks like:
QMAKE_LFLAGS = -static -enable-stdcall...

4. Save and close this file.

5. Set your environment variables. Right-click Computer >> Properties >> Advanced System Settings >> Click the "Environment Variables..." button.

6. Under "User variables," make sure QTDIR is set to your Qt path (C:\Qt\2009.05\qt). Make sure QMAKESPEC is set to win32-g++.

7. Under "System variables," edit the one called "Path." Add a semicolon ( ; ) to the end, and add the following:
C:\Qt\2009.05\mingw\lib;C:\Qt\2009.05\mingw\bin;C: \Qt\2009.05\qt\bin

8. When finished, relog or reboot.

9. Open a command prompt.

10. Change to your Qt directory by entering: cd C:\Qt\2009.05\qt

11. Enter the following: configure -static -no-phonon -no-phonon-backend -release -no-exceptions

12. When it asks which edition you want to use, enter "o" for open source.

13. When it asks you to accept the terms of the license, enter "y" for yes. This will take around maybe 10 minutes to complete.

14. When that finishes, enter the following: mingw32-make sub-src (or) nmake sub-src

15. Go out to dinner, this will take a while (took between 1-2 hours for me).

16. When this finishes, open your project in the Qt Creator.

17. Double-click the project (.pro) file to open it in edit mode.

18. Add the following line: CONFIG += static

19. qmake Hello.pro
nmake release (or) mingw32-make release

20. Navigate to your release directory and voila! Your standalone executable should be there.