Friday, September 11, 2009

The Registry and 64 bit OSes.

So, today starts the first real foray for me into the land of 64 bit OSes. This should prove interesting.

Needless to say, it's been interesting so far. Here's a tale of my first conundrum.

One of the tools we have in house reads the 3D Studio Max registry (locations on where to put custom scripts et al). So, in order to port this tool to an appropriate version of Max I need to be able to find out the value of "HKEY_LOCAL_MACHINE\\SOFTWARE\\Autodesk\\3dsMax\\11.0\\MAX-1:409\\Installdir".

So, I crack open Regedit go to this registry key and change it, intending to break the tool. I run the tool and voila, the tool behaves as normal (read: it doesn't break).

Wait, what?

I double check to ensure that the registry key has been changed (it now reads N:\NoDir), this time exit out of regedit and try again.

Same results. The tool works like before (read: as if the registry entry hasn't been changed).

OK. This is nutty. Is there some kind of security privilege going on here? If so, I shouldn't be able to change it. Aggrivation! But no, that's not the case.

One Google search later I find the following web page: http://support.microsoft.com/kb/256986

More to the point, we have the following bit of text
Note The registry in 64-bit versions of Windows XP, Windows Server 2003, and Windows Vista is divided into 32-bit and 64-bit keys. Many of the 32-bit keys have the same names as their 64-bit counterparts, and vice versa. The default 64-bit version of Registry Editor that is included with 64-bit versions of Windows XP, Windows Server 2003, and Windows Vista displays the 32-bit keys under the following node:
HKEY_LOCAL_MACHINE\Software\WOW6432Node

Oh my dear sweet zombie jesus. Are you kidding me?

No, apparently not. Wow. Just wow. So needless to say what I've been changing all along is the 64 bit app's version of the registry. Un-be-lieveable.

Oh well, something to be aware of in the future, I guess.

2 comments:

virtualmic said...

Thanks for this entry man. Rescued me from hours of trying to change HOME key for GNU Emacs registry entry on Windows XP 64 bit.

Ash said...

Glad to assist. One of the reasons I do this blog :P