[Python-Dev] Registry keys written by x64 installer

[Mark Hammond]

Martin quoting me:
> > Yes - that is a bit of a shame, as having 32bit components
> > would allow more flexibility (eg, allow a 64bit install of
> > Python to work with an IIS configured for 32bit extensions),
> > but that's something we can deal with later if necessary.
>
> Can you elaborate?

As you mention, 64 and 32bit programs use different instruction sets.
Therefore, trying to use a 64bit install of Python with IIS configured to
work with 32bits is not going to work.  In this case, switching the
configuration of IIS will require the Python user to uninstall the previous
version and install a different version - but some sites may end up in a
dilemma here - they may be *forced* to use IIS in 32bit mode due to no 64bit
port for a tool they need, but simultaneously desire a 64bit build of Python
for other tasks on that same box.

> It's incorrect for a Win64 installer to make the executable components
Win32.

Right - I got the impression from Micheal that it was possible for 32bit
components to be installed in a 64bit install, but I don't profess to know
anything about this.

> A 64 bit pythonxy.dll cannot work in
> a 32-bit IIS - it's a different instruction set. That's not something
> that you can fix by just installing things differently.

Exactly - which is why I'm suggesting that not "allowing" 64bit and 32bit
versions of Python to be installed on the same box will cause inconvenience
for some people.  I agree such people will be in the minority, and their
requirements are not clear, so I'm not pushing for a change of policy here.

> > using _winreg is (almost) like using the API directly.
> > RegDisable[/Enable]ReflectionKey appears to let the 32bit
> > process see the
> > real keys - I'm not aware of how 64bit apps would enable
> > that reflection,
> > but it probably doesn't really matter for our purposes.
>
> They can specify KEY_WOW64_32KEY.

Ah - thanks.

Cheers,

Mark