Possible Duplicate:
Qgis polygonize problem - DLL load fail

I'm getting the following error message when I try to use the polygonize tool in QGIS 1.8 (windows 7):

Traceback (most recent call last): 
File "C:\PROGRA~2\Quantum GIS Lisboa\bin\gdal_polygonize.py", line 34, in 
import gdal, ogr, osr 
File "C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\gdal.py", line 2, in 
from osgeo.gdal import deprecation_warn 
File "C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\osgeo\__init__.py", line 21, in 
_gdal = swig_import_helper() 
File "C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\osgeo\__init__.py", line 17, in swig_import_helper 
_mod = imp.load_module('_gdal', fp, pathname, description) 
ImportError: DLL load failed: No se encontró el proceso especificado. 

I can perform this operation with the same raster file on QGIS 1.7 on this very same computer. (This is for a class I'm giving and all the students have installed 1.8).


1 Answer 1


Could you try adding C:\PROGRA~2\Quantum GIS Lisboa\bin\ to the beginning of your PATH variable and see if it works?

Is C:\QGIS\python (or C:\Python26\Lib\site-packages\PyQt4\bin ) or something similar in your PYTHONPATH environment variable? You might want to remove it. This seems like Python module version mismatch. QGIS 1.7 uses Python 2.6 while 1.8 uses 2.75. I'm betting that QGIS 1.8 is getting the DLLs for QGIS 1.7 as it may be in your PYTHONPATH.

  • Hmm. I have no PYTHONPATH variable declared in my environment variables. Any other possibility?
    – user12384
    Oct 31, 2012 at 14:15
  • Updated my answer. I hope it will work this time.
    – R.K.
    Nov 1, 2012 at 13:42
  • Adding C:\PROGRA~2\Quantum GIS Lisboa\bin\ to begginning of PATH variable didn't do the trick. Still have the same error message.
    – Andres
    Nov 5, 2012 at 20:37
  • Could you check if it will work if you remove the trailing backslash? C:\PROGRA~2\Quantum GIS Lisboa\bin
    – R.K.
    Nov 6, 2012 at 7:30

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