[Tutor] Changing Default Install Path on Windows

Luke Paireepinart rabidpoobear at gmail.com
Wed Apr 21 09:40:54 CEST 2010

Hi guys,
my first post to the list with a question rather than a response in a
few years, I think :)

(NOTE: I solved my question while writing this e-mail, I'm just
mailing this to the list for future users now)

I'm running Windows 7 64-bit.

I currently have 3 python installs.
First I installed the 64-bit version of Python 2.6 to C:\Python26,
then realized that it doesn't have as much lib support.
Then I installed the 32-bit version to C:\Python26x86
Everything worked fine after this (installs, etc. all went to the
proper site-packages.)

Then I installed Panda3D and normally it doesn't hijack your Python
install but I guess in this case I accidentally told it to become

Now, when I try to run an installer, it finds the Panda3D Python first.

I'm getting really frustrated because I can't figure out why it's
finding the Panda3D Python.
I don't understand how the multiple version precedence works.

In my registry, HKLM / SOFTWARE / Python, all I have is PythonCore/2.6
and all references in here (PythonPath, InstallPath, etc. etc.) all
reference the FIRST python install (C:\Python26)

My PATH environment variable is:
C:\Users\rabidpoobear>echo %path%

C:\Program Files (x86)\PC Connectivity
Solution\;C:\Python26x86\Lib\site-packages\PyQt4\bin;C:\Program Files
(x86)\NVIDIA Corporation\PhysX\
C:\python26x86;C:\Program Files

the Panda3D bin directory does NOT contain a python.exe, it only
contains panda3d stuff.  The Panda3d python install is in

I cannot find any references to the Panda3D python install ANYWHERE.

Yet anytime I try to run an installer, it tries to install there.  And
the stupid "helpful" python installers that auto-find the directory do
not let you change it.
They make the (faulty) assumption that they're correct.


I figured out the solution, I just did a Find on my entire registry
and found C:\Panda3D-1.7.0 in
HKLM\Software\Wow6432Node\Python\PythonCore\2.6\InstallPath .
After some investigation it seems that the special Wow6432Node has to
do with 64-bit versions of Windows running 32-bit versions of Python.

So the lesson we've learned today is that your 64-bit Python install
path should will be where it normally is
but your 32-bit path will be in that special WowNode directory.

Hope that helps someone in the future,

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