I have the following external method to back up a postgres database, using the following software versions. Zope Version (Zope 2.9.0, python 2.4.2, win32) Python Version 2.4.2 (#67, Sep 28 2005, 12:41:11) [MSC v.1310 32 bit (Intel)] System Platform win32 Zope is running as user scholarpack who is an administrator on win server 2008. / import subprocess def backup(): try: p=subprocess.Popen("c:/scholarpack/postgres/bin/pg_dump scholarpack",shell=True,stdout=subprocess.PIPE) data=p.communicate()[0] f=open('c:/scholarpack/ancillary/scholarpack.sql','w') w=f.write(data) f.close() except OSError: print "There was a problem opening the file for writing" /When I run this through Zope I get an empty file. There are no errors reported. However, if I use the same python that is running zope in an interactive shell and run these commands then it works as expected. Can anyone spot what I am obviously missing? Regards Garry