I have a working Python 2.6 install and just installed the PyQt4 built for Python 2.6 (available at http://www.riverbankcomputing.co.uk/software/pyqt/download). When I try to import PyQt4.QtGui I get the following error:
ImportError: DLL load failed: The specified procedure could not be found.
I'm on Windows 2k8 64-bit, but my Python install is 32-bit.
Add the the PyQt4 directory containing Qt's applications and DLLs to your PATH environment variable. In PowerShell, provided you didn't change any of your install paths, that'd be
$env:path += 'C:\Python26\Lib\site-packages\PyQt4\bin'
If this does not works, try search for QtCore4.dll, QtGui4.dll, etc. in your paths set in PATH environment variable. In my case I found some qt dll in c:\windows\system32, caused the same error message. I've deleted the dll files, and problem solved. 'C:\Python26\Lib\site-packages\PyQt4\bin' was in my path, but that was not enough.