From: ptkwt@... (Phil Tomson)
Date: 2003-12-30T12:36:47+09:00
Subject: Re: (FYI)Accessing WinXP-64bit registry items

In article <c68ca8f2.0312291659.7c864268@posting.google.com>,
Phil Tomson <intc_ctor@yahoo.com> wrote:
>There probably aren't a lot of WinXP-64bit users out there yet, but I
>post this for future reference:
>
>I was using the win32/registry (as in 'require "win32/registry"')
>package to access the registry to figure out if certiain apps were
>installed on a Windows box.  The script worked fine on my Win2K box,
>but when someone tried it on their WinXP-64bit edition box it didn't
>find the installed apps as it should have.
>
>Turns out that in 64bit windows there are two sections to the
>registry, a 32bit section and a 64bit section.  I couldn't see the
>64bit apps from the Ruby script (using the standard Ruby install
>created by Andy Hunt, so it's 32 bits).  After some research, I found
>out that you've got to add some new registry access rights.
>
>The solution is that you need to add some new access rights keys in
>your Win32::Registry::Constants module:
>
>      KEY_WOW64_64KEY = 0x0100
>      KEY_WOW64_32KEY = 0x0200
>
>And then OR them into KEY_READ:
>
>      KEY_READ = STANDARD_RIGHTS_READ | KEY_WOW64_64KEY |
>KEY_WOW64_32KEY |
>        KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS | KEY_NOTIFY
>
>After I did that it worked fine � I was able to see the 64bit registry
>entries.
>
>How's that for obscure? ;-)
>
>You can find more info here:
>
>http://msdn.microsoft.com/library/default.asp?url=/library/enus/sysinfo/base/registry_key_security_and_access_rights.asp
>
>I've notified Usa Nakamura who I'm told is the registry.rb maintainer,
>so hopefully, by the time you need this in the 64bit future it will
>work OK out of the box.
>

Well, I spoke a bit too soon...  Sure it works on 64-bit Windows, but it 
breaks now on 32-bit Windows.

Looks like we need to come up with some reliable way to determine if 
you're running on 64bit WinXP or 32Bit WinXP and then do something like:

  KEY_READ |= (KEY_WOW64_64KEY | KEY_WOW64_32KEY)  if XP64

Any ideas for how to determine XP64?

Phil