python - How to fix Qtcore4.dll can't find procedure entry point?

Possible Duplicate:
How to fix QGIS error “Entry Point could not be located”?

I am working with QGIS, python2.5 and pyqt4 for py2.5. My system variables are as follows:

path:=C:\Program Files\Quantum GIS Wroclaw\apps\qgis\bin;C:\Python25;C:\Program Files\Quantum GIS Wroclaw\apps\qgis;

pythonpath:=C:\Program Files\Quantum GIS Wroclaw\apps\qgis\python;

But when i try to run a .py file through the command shell it gives me this error:

python.exe-entry point not found. 
The procedure entry point: ??0QDataStream@@QAE@PAVQByteArray@@H@Z could not be located in the dynamic link library QtCore4.dll

Qtcore4.dll is present in Qgis folder, why does the error occur? and it is not present in system 32 so what do i do then? it was present then i deleted it it still says that.